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Table of Contents

Part I

On the variation of organic beings under domestication and in their natural state

Chapter I. On variation under domestication and on the principles of Selection. p to

Chapter II.  On variation of organic beings in a state of nature; on the natural means of Selection; on the comparison of domestic races, & true species

Chapter III   On the variation of Instincts and other mental form attributes; on the difficulties in this subject; and on analogous to difficulties with respect to corporeal structures.  p. to

Part. II.

On the evidence favourable & opposed to the view that species are naturally-formed races, descended from common stocks.

Chapter I. On the number of intermediate forms, required on the theory of common descent, & on their to  absence in a fossil state.  p. to

Chapter II. Gradual appearance & to disappearance of species. p. to

Chapter III.  Geographical distribution of organic beings

 Sect I.      in present times:  p. to   

Sect II.     in past times:  p. to  

   Sect III     explana origin of the laws of distri[text excised]

Chapter IV.    Affinities & classification of organic beings.

Chapter V.     Unity of type & morphological structures  p

Chapter VI.    Abortive or rudimentary organs. p

(over

[The page numbers in pencil (not transcribed here) were added by Francis Darwin.]

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Chapter VII.    Recapitulation and Conclusion.  p. to

 

(This was written & enlarged from a sketch in 37 pages in Pencil (the latter written in summer of 1842 at Maer & Shrewsbury) in beginning of 1844, & finished it this in July; & finally corrected the copy by Mr Fletcher in the last week in September.)

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(A)  Food & climate, & other unknown causes will occasionally produce changes in the colour & texture of the external texture coverings of animals during their individual lives; and certain unknown conditions affect the horns of cattle in A parts of Abyssinia: but whether in these cases actual peculiarities thus acquired thus acquired during the individual lives of these animals have been inherited, I do not know. but when congenital,

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Part I

Chapter I

On the variation of organic beings under domestication and on the principles of Selection.

The most favourable conditions for variation seem to be, when an organic beings are is bred for many generations under domestication: one may infer this, from the simple fact of the vast number of races, and breeds, which of almost every plant & animal, which has long been domesticated. If we look to the steps Under certain conditions even organic beings, even during their individual lives, become slightly altered, & in & such changes from their parent form are often from their usual, form, size, or other characters and many of the peculiarities thus acquired are transmitted to their offspring. Any Even the most trifling peculiarity, when heredetary, gives to. Thus in animals, the size and vigour of body, fatness, period of maturity, habits of body or consensual movements, habits of mind & temper, quiet quickness are modified or acquired during the life of the individual animals & become inherited. There is reason to believe that when long exercise has given to certain muscles them great development, their or disuse has lessened them, that such development is heredetary also inherited. (A) It appears certain that mal-conformation & Lameness in horses, produced by too much work on hard roads — that blindness affections of the eyes; in this animal probably caused by bad ventilation — that numerous tendencies toward many diseases in man, such as gout,, affect caused by the course of life & ultimately producing producing changes of structure,— and that many other diseases dependent on some produced caused by unknown local agencies, such as goitre, & plica-polonica & idiotcy resulting from it all become heredetary.)⁋ We further There is no evidence or not sufficient evidence that any mutilation, or change of form produced by mechanical process even if continued for the hundreds of generations, or that any change in structure if suddenly quickly produced by diseases, is inherited

⁋ (It is very doubtful whether the flowers & leafbuds annually produced from the same bulb, root, or tree can properly be considered as parts parts of an individual the same individual, though in some respects they certainly seem to be so; if so., these plants

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are subject to considerable changes during their individual lives. Most florists-flowers will, if treate neglected degenerate, that is lose some of their characters;; so common is this, that trueness trueness is given often stated, as greatly enhancing the value of a kind variety: tulips break their colours only after some years culture; some plants become double & others simple by neglect or care: these characters can be transmitted by propagated by slips transmitted by cuttings or grafts, & in some degree cases by true or seminal propagation. Occasionally a single bud on a plant assumes suddenly at once a new & widely different character: thus it is certain that nectarines have been produced on peach-trees & moss-roses on Provence roses bushes; white currants on red-currant bushes; diff flowers of a different colour from that of the stock, in Chrysanthemums, Dahlias, sweet-william azaleas azaleas, orchids orchideaceous epiphytes &c &c; variegated leaf -buds on many trees, & other similar cases. These peculiarities in new characters appearing in individual buds, can, like those lesser ones affecting changes affecting the whole plant stock, be multiplied not only by cutting & such means, but often likewise by true seminal generation.)

(The changes thus appearing during the lives of individual animals and plants, are rare extremely few rare compared with those which are congenital or which appear soon after birth. or soon directly afterwards. Slight differences thus arising are infinitely numerous: the proportions & form of every part of the form frame inside & outside, appear or can often to vary in very slight degrees; anatomists dispute what is the 'beau ideal' of the bones, the liver, & kidneys, as much as like painters do of the proportions of the face: the proverbial expression that no two animals or plants are born absolutely alike, is slightly much truer when applied to those under domestication, than to those in a state of nature. Occasionally Besides these slight differences, single individuals are occasionally born, considerably unlike in certain parts or in their whole of their structure, from to their parents: these are called by horticulturists & breeders, "sports"; when the difference is as considerable strongly marked as in the possession of an extra-limb, as

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by the Dorking-fowl, or in the extreme shortness of the limbs in all four legs, as in the ancon sheep, it may be called an inherited monstrosity. for there seems (A) on the size, colour & form, which can rarely & obscurely be detected in the during one individual life, become apparent after several generations: the slight differences, often hardly describable, which characterize the stocks of different countries, & even of districts in the same country, seem to due to external influences. such continued action.)

In the few cases instance, when the history of a species, as of the Dahlia, is known, from which many varieties have proceeded

In the few instances, as in the Dahlia, in which the course of variation, it appears that domestication produces little effect in

(B): in the Second Part, I shall have to discuss at which period of the embryonic period life, congeni connatal peculiarities probably first appear; & I shall then be able to show from some evidence, that at whatever period of life, a new peculiarity fir first appears, it tends to heredetarily to appear at this same a corresponding period.

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and are not very uncommon, except at least the when very strongly marked. they are, however, very rare. These Such sports are known in some cases, to have been & in many others are probably, are the to be the first parents of many some of our domestic races; & such probably are have been the parents of many other races, especially of those which in some senses might may be called heredetary monsters;— for instance where there is an additional limb, or where all the limbs are stunted (as in the ancon ancon sheep), or where a part is wanting as in rumpless fowls & tailess dogs or cats. The effects of external conditions. (A)

(A volume might be filled with facts, showing what a strong tendency there is to inheritance, in almost every case of the most trifling, as well as of the most remarkable congenital peculiarities. The term congenital peculiarity, I may remark, is a loose expression when applied generally, for the period of birth varies much in different animals with respect to the degree of development of the embryo; and as many parts of the body are imperfectly or not at all developed (as with in case of horns) at birth, peculiarities appearing to in them cannot be congenital. & can properly only mean a peculiarity apparent when the part in quest affected, is fully or nearly or fully developed, (B) & other parts, as horns of cattle are developed only after birth. & therefore cannot [illeg] peculiarities.

Numerous, though slight changes, slowly supervening in animals during mature life, & any (often though by no means always taking the form of disease,) are, as stated in the first paragraphs also very often heredetary. Buds In plants, again, the buds which assume a different character from their common stock likewise tend to transmit their new peculiarities. There is not sufficient reason to believe that either mutilations or changes of form produced by mechanical pressure, even if continued for hundreds of generations, or that any changes of structure quickly produced by disease, are inherited; it would appear as if the tissue of the part affected must slowly & but freely grow from its own impulse into the new form, in order to be inheritable. There is a very great difference in the heredetary tendency of different peculiarities, or and of the same peculiarity, in different seeds individuals and and species; to be inherited thus 20 thousand

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seeds of the weeping ash have been sown & not one came come up true;— out of 17 seeds of the weeping yew, nearly all came up true. all but one of the fastigiate Irish yew have individually produced their kind. Here peculiarities characterizing The ill-formed & almost monstrous 'niata' cattle of S. America & of the ancon sheep, when purebred & when crossed with other breeds, seem to transmit their peculiarities to their offspring than with fully as much if not more power than the old common breed. as truly, as the ordinary breeds., Breeders I can throw no light on these differences in the power of heredetary tendencies. transmission. Breeders believe, & apparently with good cause, that a peculiarity generally becomes more firmly implanted after having passed through several generations; that is if one offspring out of twenty inherits a peculiarity from its parents, then its descendants will tend to transmit this peculiarity to an increasing a larger proportion than one in twenty; & so on in succeeding generations. I have said nothing about mental peculiarities being inheritable for I reserve this subject for a separate chapter.

Attention must here be drawn to an important distinction in the first origin or appearance of varieties: when we see an animal highly kept producing offspring with an heredetary tendency to early maturity & fatness; when we see the wild-duck & Australian duck dog always becoming in when bred for one or a few generations in confinement mottled in their colours; when we see people living in certain districts or circumstances becoming subject to an heredetary taint to certain organic diseases, as consumption goitre or plica polonica,— we naturally attribute such changes to the direct effect of known or unknown agencies, acting for one or more generations on the parents. (We know that the effects of habit become heredetary if [illeg]) It It is probable that a multitude of peculiarities may be thus directly caused by unknown external agencies. But when we in breeds, characterized by an extra limb as in or claw, as in certain

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fowls & dogs; by an extra joint in the vertebræ; by the loss of a part, as the tail; by the substitution of a tuft of feathers for a comb in certain poultry; & in a multitude of other cases, we can hardly attribute these peculiarities toto directly to external influences, but indirectly to the laws of embryonic growth & of reproduction. When we see a multitude of varieties ( as is has often been the case, where a cross has been carefully guarded against) produced from the very seeds matured in the very same capsule, and with male with the male & female parent principle nourished from the same roots, & necessarily exposed to the same external influences; we cannot believe that the endless slight differences between all the various many seedling- varieties thus produced, can be the effect of any corresponding difference in their exposure. We are led (as Müller has remarked) to the same conclusion, when we see in the same litter, produced by the same act of concepcion, animals considerably different. Although the varieties, thus, in such cases, do not appear to have As variation to the degree here alluded to, has been observed only in organic beings under domestication, & in a in plants amongst those most highly and long cultivated, we must attribute the in such cases, the varieties in the seedlings from the same capsule ( although the difference between each variety cannot possibly be attributed to any corresponding difference of exposure in their parents) to the indirect effects of domestication on the action of the reproductive system. It would appear, as if the reproductive powers system failed in their ordinary function of producing new organic beings, closely like their parent; ones; and as if the entire organization of the embryo, under domestication, became in a slight degree plastic. We shall hereafter have occasion to show, that any changes in an organic beings, a considerable change from the natural conditions of life, affects, independently of their general state of health, in

another &

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remarkable manner, the reproductive system. I may add, that judging from the vast number of new varieties of plants which have been produced in the same districts & under nearly the same routine of culture, that probably the indirect effects of domestication in making the organization plastic, is a much more fertile efficient source of variation, than any direct effect, which external causes may have on the colour, texture or form of each part. In the few instances, in which (A) We have hitherto spoken only of the first appearance in individuals of of varieties inheritable peculiarities in individuals, either congenital or gradually appearing; whether during their mature life or before their birth; of the individual; but to make a race, except in the case of the its peculiarity being the direct effect of constantly surrounding conditions, this is characterized in most cases something more is required than that this peculiarity its peculiarity shall be inheritable, namely natural the principle of natural selection; implying separation. Even in the rare instances of strongly marked sports, with the heredetary tendency very strongly implanted, in animals both sexes must be so characterized & in n[illeg]t plants a cross prevented, or if both sexes are not so characterized crossing must be prevented with other breeds, or if not prevented the best characterized of the halfbred youngoffspring must be carefully selected. Even Again When, the, also, the external conditions are constantly tending to give some character, a race so possessing characterized this character will be formed, with far greater ease by selecting & breeding, together the individuals most affected. In the case of the endless slight variations, produced by the indirect effects of domestication on the action of the reproductive system, selection is indispensable to form races; but and when carefully applied, wonderfully numerous & diverse races can be formed. Selection though so simple in theory, is & has been important to a degree, which can hardly be overrated. It requires when practically extreme skill, the result of long practice, in detecting the slightest difference in the forms of animals, & it implies some distinct object in view; with these requisites & patience, the Breeder has

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(A)

, as in the Dahlia, the course of variation has been recorded, it appears that domestication produces little effect for several generations in rendering the organization plastic; & then but afterwards, as if by an accumulated effect the original character of the species suddenly gives way or "breaks".) Here is, perhaps, an anodyne result, from the that the seedlings from the same capsule of those plants, which are generally propagated by slips grafts, tubers & therefore successively are exposed to the varied accumulating influences of culture, vary to such an extraordinary degree, far more than in the same litter or hatch of co-descendants any animal., or bird, or I believe of any plant, which is usually propagated by seed.

(We have hitherto only referred to the first appearance in individuals of new peculiarities; but to make a race or breed, something more is almost generally requisite than than such peculiarities (except in the case of the peculiarities being the direct effect of constantly surrounding conditions) should be inheritable,— namely the principle of selection, implying

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(A)

In most cases, this careful selection & the prevention of accidental crosses will be necessary for many several generations; for in new breeds there is a strong tendency to vary & especially to revert to ancestral forms: but in every succeeding generation less selection care will be requisite for the breed will become truer; until ultimately only occasionally an single occasional individual, will require to be separated or destroyed: Horticulturist in raising seeds, regularly practice this, and call it roguing, or destroying the 'rogues' or false varieties. There is another & less efficient means of selection am amongst animals; namely taking repeatedly procuring males with some desirable qualities & allowing them & their offspring to breed freely together; A still less efficient, and this in the course of time will affect the whole lot. (B) These principles of selection have not been methodically followed in Europe for scarcely for [illeg] it scarcely more than half three quarters of a century, but the results in England are great.

B Even in well established breeds, the individuals of which to an unpracticed eye would appear absolutely similar, & which would give, it might have been thought, give no scope to selection, the whole appearance of the animal has been changed, in a few years (as in the case of Ld. Western's sheep) so that the practiced agriculturalists could scarcely believe credit, that the change had not been effected by a cross with other breeds. ) Breeders both of plants & animals frequently give their means of selection greater scope, by crossing different breeds ; & we shall presently allude to this & selecting their offspring; but we shall have to recur to this subject again.)

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simply to watch for every the slightest smallest approach to the desired end, to select such individuals & pair them with the most suitable forms, & so continue with succeeding generations. (A) This practice results of the practice are shown by what has been effected by agriculturists & in a lesser degree by horticulturists has been systematically followed only during the last half century; a century; but their high importance as is admitted both shown by the practical work & results & are is admitted in the writings of the most celebrated agriculturists & in a lesser degree of to horticulturists;— I need only name Anderson, Marshall, Bakewell, Coke, Western, Sebright, & Knight. (B) (The External conditions will doubtless influence the & modify the results of the most careful selection; it has been found impossible to prevent certain breeds of cattle from degenerating on mountain pastures; it would probably be impossible to keep the plumage of the wild duck in the domesticated ra state race; in certain soils, no care has been sufficient to raise keep cauliflower seed, true to its character; & so in many other cases. But with patience, it is wonderful what man has effected: he has selected & therefore in one sense made one race breed of horses to race & another to pull;— he has made sheep with fleeces good for carpets & other sheep good for broadcloth;— he has made in the same sense made one dog to find game & give him notice of it when found, & another dog to fetch him the game when killed;— he has made the fat to be mixed with the meat in one breed, & in another to accumulate in in the bowels for the tallow-chandler;— he has made the legs of one breed of pigeons long, & the beak of another so short, that it can hardly feed itself;— he has previously determined how the feathers on a birds body shall be coloured, & how the petals of many flowers shall be streaked or fringed & has given prizes for complete success;— he has made

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the leaves of one variety & the flower-buds of another variety of the same plant of the cabbage good to eat, both at different seasons of the year; & thus has he acted on endless varieties. I do not wish positively to affirm, that the long- & short wooled sheep, or that the pointer & retriever, or that the cabbage & cauliflower have certainly descended from one & the same aboriginal wild stock; but for and if they have not so descended, though it lessens what man has effected, a large result must be left unquestioned. In saying, as I have done, that man makes a breed, let it not be confounded with saying that man makes the individuals which were are given by nature with certain desirable qualities;, man only adds together & makes a permanent gift of nature's bounties. In several some several cases, indeed, for instance in the 'ancon' sheep, good for not getting over fences, & in the turnspit dog — in the teazle for carding wool — man has probably only prevented crossing; but in many cases we positively know that he has gone on selecting, altering & taking advantage of successive small variations.)

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: such care shows at least that the characters of individual animals were attended to.

(a)

In the rudest times of English history, there were laws to prevent the exportation of fine animals of established breeds, & in the case of horses, in Henry VIII. times, laws for the destruction of all horses under a certain size. In one of the oldest numbers of the Phil. Transactions, there are rules for selecting & improving the breeds of sheep.— Sir H. Bunbury, in 1660, has given rules for selecting the finest seedlings & plants, with as much precision, as the best recent Horticulturist. Even in the most savage and rude nations, in the wars and famines, which so frequently occur, the most useful of their animals would be preserved: the value set upon animals by savages is shown by the inhabitants of Tierra del Fuego devouring their old women before their dogs, which as they asserted are useful in otter-hunting: who can doubt but that in every case of famine & war, the best otter-hunters wd. be preserved, & therefore in fact selected for breeding. as the offspring so obviously take after their parents, & as we have seen that savages take pains in crossing their dogs & horses with wild stocks, we may even conclude as probable, that they would sometimes so pair the most useful of their animals & keep their offspring separate.

(B) by which new breeds are not sep selected & kept separate, but a peculiar character is unintentionally slowly given steadily to the whole mass of the breed, by always generally preferring often saving the life & even & preferring for breeding of animals with certain characteristics,

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(Selection has been methodically followed, as I have said, for at least scarcely barely a century; but it cannot be doubted that occasionally it has been practiced from the remotest ages, in those animals completely under under the dominion of man. In the earliest chapters of the Bible there are rules given for influencing the colour of breeds; & black & white sheep were are spoken of as separated. In the time of Pliny the Barbarians of Europe & Asia endeavored by cross-breeding with a wild stock to improve the races of their dogs & horses. The savages of Guyana now do so with their dogs.—(a)

That the offspring take after their parents is so obvious, that the most useful animals would be taken greatest as case of in the wars & famines of savage life (as dogs before old women in Teirra del Fuego & would be most carefully bred from. As different races of man require & admire different kinds of beasts qualities in their domesticated animals, the process each would thus slowly & insensibly,, though unconsciously, be selecting a different breed: As Pallas has remarked who can doubt,. but that the ancient Russians would esteem & longest endeavor to preserve those sheep in his flock which had the warmest thickest coats. This kind of insensible selection, (B) we may feel nearly sure, from what we see has been done by the more direct method of separate selection within the last 50 years in England, would in the course of some thousand years, produce a marked effect.—)

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(When once two or more races have been are formed, or if two o such more than one race, or species fertile inter se, originally existed in a wild state, their crossing becomes a most fertile source of new races. When two well-marked races, are crossed, the offspring in the first generation take more or less after either parent or are quite intermediate between them, or rarely assume some characters in some degree new. In the second & several succeeding generations, the offspring are generally found to vary exceedingly, one compared with another, & may revert nearly to their pare ancestral forms. This greater variability after in succeeding generations seem analogous to the first breaking or variability of organic beings, after having been being reared for bred for some generations under domestication. So marked is this variability in the cross-bred descendants, that Pallas & some other naturalists have supposed that all variation is originally due to an original cross; but I conceive that the history of the Potato, Dahlia, Scotch Rose the guinea-pig, & many trees in this country, when only one species of the genus exists, clearly shows, that a species may vary, where there can have been no crossing. Owing to this variability & tendency to reversion in cross-bred beings, much careful selection is requisite to make intermediate or new permanent races: nevertheless this crossing has been a most powerful engine, especially with plants, where means of propagation exist by which present the cross-bred the varieties can be secured, without risk incurring the tendency to seminal variation. risk of fresh variation from seminal propagation: with animals, the most skillful agriculturalists now greatly prefer careful selection, though with less scope of variation, from the same stock a permanent breed; to rather than from uncertain cross-bred races stocks.)

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Although intermediate and new races may be formed by the mingling of others; yet if two races are not very allowed to mingle quite freely, so that none of either parent race are left remain pure, then, especially if the parent races were are not different, they will slowly blend together, & the two races will be destroyed & a mongrel one left in its place. It is We see this This will of course happen in a shorter time if one of the parent races exists in greater numbers than the other. We see the effect of this mingling, in the manner in which the aboriginal breeds of dogs & pigs in the Oceanic Islds. have been lost in a mongrel and the many breeds of our domestic animals introduced breeds into S. America, have all been lost & absorbed in a mongrel race,. It is probably owing to the freedom of crossing, that, in uncivilized countries, where enclosures do not exist, that we seldom meet with more than one race of a species: it is only enclosed countries, where the inhabitants do not migrate & with conveniences for separating the several kinds kinds of domestic animals, that we meet with a multitude of races of the same species. Even in civilized countries, want of care for a few years has been found to destroy the good results of far longer periods of selection & separation. This power of crossing will affect the races of all terrestrial animals; for all terrestrial animals are bisexual require for their reproduction the union of two individuals. This was oris also necessary in a far greater number of marine animals. Amongst plants, races will not cross & blend together, with so much freedom, as in terrestrial animals, but this is effected takes place through various curious mechanical contrivances to a surprising extent. In fact in so very many hermaphrodite flowers, I believe with few exceptions,

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such many contrivances & means exist, by which an occasional cross may take place, that I cannot avoid suspecting that the reproductive action requires in every case the occasional concurrence at intervals the concurrence of distinct individuals. & even of distinct families. Most breeders of plants & animals are firmly convinced, that not only benefit is derived from an occasional cross, not with another race, but with another family of the same race; & that, on the other hand, injurious consequences follow from long- -continued close interbreeding in the same family. Of marine animals, many more, than was till lately believed, have their sexes on separate individuals; & where they are hermaphrodite, there seems very generally to be means through the water, of one individual occasionally impregnating another: if a single individual animals can singly propagate itself themselves for perpetuity, it is singular unaccountable that no terrestrial animals where the means of observation are more obvious should have be in this predicament. I conclude, then, that m races of most animals & plants, when unconfined in the same country would tend to blend together.)

(Several naturalists of whom Pallas, I believe was one of the first, regarding animals, & Humbolt regarding certain plants believe that the breeds of many of our domestic animals such as of the horse, pig, dogs sheep. pigeons & poultry have descended from more than one aboriginal form: They leave it doubtful, whether these such forms are to be considered wild races, or true species, whose offspring are fertile when crossed inter se. The main arguments for this view, consist; first, of the great differences between such races breeds as the Race & Cart Horse, or the greyhound & Bull-dog & of our ignorance of the steps or stages, through by which these could have passed from a common parent; and secondly that in the most ancient earliest historical periods, breeds somewhat resembling

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some of those at similar to the present most different, ones, existed in different countries. The wolf wolves of N. America & of Siberia are thought to be different species; & it has been remarked, that the dog belonging to the savages of in these two countries resembles each the wolf of the same country, & therefore that they have probably descended from two different wild stocks. as In the same manner these naturalists would assert believe, that the Horse of Arabia & of Europe have probably descended from two wild stocks, perhaps probably, in each case both apparently now extinct. I do not think the assumed fertility of these wild stocks any very great objection to difficulty on this view; for although in animals the offspring of most cross-bred species are infertile, it is not always remembered, that the experiment is not never very seldom fairly tryed, until except when two near species are both domesticat breed freely under domestication when taken by man; & breeding freely out of a wild state (a subject to which we shall refer again) (which does not readily happen, as we shall hereafter see) when under the dominion of man. Moreover in the case of the China & common goose, the canary & siskin, the hybrids breed freely; in other cases the offspring of a hybrid with either pure parents, are fertile, as is practically taken advantage with the yak & cow;; as far as the analogy of plants serves, it is impossible to deny that some species are quite fertile inter se; but to this subject we shall recur.)

 

(On the other hand, the upholders of the view that all dogs the several breeds of dogs, horses &c &c, have descended each from one stock, may aver that their view removes all difficulty about fertility, & that the main argument from the high antiquity of different breeds, somewhat similar to the present breeds, is worth little, without we knew knowing that the date

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of the domestication of such animals, which is far from being the case. They may, also, with more justice aver weight aver, that, knowing that organic beings under domestication do vary in some degree, the argument from the great difference between certain breeds is without worth nothing, without we know the limits of variation during a long course of time, which is far from the case. They may argue that almost every county in England, & in many districts of India other countries, for instance in India, there are breeds slightly different breeds of the domestic animals; & that it is opposed to all that we know of the distribution of wild animals, to suppose that these have descended from so many different wild races or species: if so, they may argue, is it not probable that countries more quite separate & exposed to different climates, would have breeds not slightly, but considerably different. Taking the most favorite case on both sides, namely that of the dog; they might urge that, surely such breeds as the Bull-dog & turnspit have been reared by man, knowing that the origins of strictly analogous breeds namely the niata ox & ancon sheep have is ascertained amongst oxen & sheep. other quadrupeds. Again they may say, seeing what training & careful selection has done effected for the greyhound, and seeing how absolutely unfit the Italian Greyhound is to live maintain itself in a state of nature, is it not probable that at least all Greyhounds, from the Rough Deer, the smooth Persian, the common English, to the Italian have descended from one stock? If so, is it in so improbable that the Deer-Greyhound & long-legged shepherd dog have so descended? If we admit this & give up the Bull-dog, we need not doubt concerning of the can hardly positively dispute the probable common descent of any the other breeds.)

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The conjectured evidence is of that nature & is far [illeg] so conjectured and balanced on both sides, that at present, I conceive no one can decide: for my own part, I lean to the probability of most of our domestic animals having descended from more than one wild stock; though, from the arguments last advanced & from reflecting on the constant slow, though inevitable effect of different races of man, under different circumstances, preferring saving the lives of & therefore selecting of the individuals most useful to them, I cannot doubt but that one class of naturalists have much overrated the probable number & differences of the wild stocks. As far as we admit the difference of our races is due to the differences of their wild original stocks, so much must we give up of the amount of variation produced under domestication. But this appears to me unimportant, for we certainly know, in some few cases, for instance in the Dahlia & Potato that a considerable amount great number of varieties has been produced proceeded from one stock; & in many of our domestic races, we know that man by slowly selecting, & by taking advantage of sudden sports, has considerably modifyed old races & produced new ones.. Whether we consider our races as the descendants of one or several wild stocks, we are in all almost every case, quite far the greater number of cases, equally ignorant, what these stocks were.)

 

(Man's power in making races depends in the first instance on the stock, on which he works being variable; but his labours are is modifyed & limited, as we have seen, by the direct effects of the external conditions,— by the deficient or imperfect or de heredetariness of new peculiarities of the first or succeeding

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generations,— & by the tendency to continual varying variation vary & especially to revert reversion to ancestral forms. If the stock is not variable under domestication, of course he can do nothing; & it appears that species differ considerably in this tendency to variation, in the same way, as even sub-varieties from the same variety differ greatly in this respect, & transmit to their offspring this difference in tendency. Whether the absence of a tendency to vary is an unalterable quality in certain species, or depends on some deficient element condition of the particular state of domestication, to which they are exposed, there is no evidence. When the organization is rendered variable, or plastic as I have expressed it, under domestication, different parts of the frame vary more or less in different species: (A) As a general rule the less important parts of the organization seem to vary most, but I think there is sufficient evidence that every part occasionally varies in a slight degree. Even when Even when man has the primary requisite variability, he is necessarily checked by the life & health & life of the stock, he is working on: thus he has already made pigeons with such small beaks that they can hardly eat & will not rear rear their own young; he has made families of sheep with so strong a tendency to early maturity & to fatten, that in certain pastures they cannot live from their extreme liability to inflammation; he has made (ie selected) sub-varieties of plants, with a tendency to such early growth, that they are frequently killed by the seaso spring frosts; he has made a breed of cows, with having calves with such large hinder quarters, that they were are born with great difficulty, often to the death of their mothers; the breeders soon remedied were compelled to remedy this by the selection of calves cows a breeding stock with smaller hinder quarters: in such

17v

(A)

: thus in the breeds of cattle, it has been remarked, that the horns are the most constant or least variable character, for these often remaining constant, whilst the colour, size, proportions of the body, tendency to fatten &c vary; in sheep, I believe, the horns are very much more variable.

18v

(13E

a case, it is, however, it is possible that by long patience & the great loss a remedy might have been found, in selecting cows capable of giving birth to calves with large hinder quarters. Besides the limits already specifyed, there can be little doubt that the variation of different parts of the frame are connected together by many laws: thus the two sides of the body in health & disease seem almost always to vary together: it has been asserted by breeders, that if the limbs are head is much enlongated, the bones of the head extremities will likewise be so; in seedling-apples, large leaves & fruit generally go together, & serve the horticulturist as some guide in his selection; we can here see the reason, as the a fruit is only a metamorphosed leave leaf. In animals the teeth & hair seem connected, for in the hairless breeds of Chinese dog is are almost toothless. Breeders seem to the believe that one part of the frame or function being increased, d[illeg] causes another other parts, from nourishment being drawn from it, to to decrease: they dislike great horns & great bones as so much flesh lost; In in hornless breeds of cattle, certain bones of the head become are more developed; it is said that fat accumulating in one part, checks the its accumulation of in another, & likewise the checks the action of the udder. The whole organization is so connected, that it is probable, there are multitudes of are many conditions, determining the variation of each part, & causing other parts to vary with it; & man in making new races, must be limited & ruled by all such laws.)

(In this chapter we have treated of variation under domestication, & it now remains to consider, in what does this

19

(13F

power of domestication consist — a subject of considerable difficulty. Observing that organic beings of almost every class, in all climates, countries & times have varied when long bred under domestication, that is we must conclude that the influence is of some very general nature. McKnight alone, as far as I know, has tried to define it; he believes it consists of an excess of food, together with transport to a more genial climate or protection from its severities. I think we cannot admit this latter proposition, for we know how many vegetable products, aborigines of this country, here vary, when cultivated , without any protection from the whether weather; & some of our variable trees, as apricots, peaches, have undoubtedly been derived from a more genial climate. There appears to be much more truth in the doctrine of excess of food being the cause, though I much doubt whether this is the sole cause, although it may well be a requisite for the kind of variation, desired by man, namely excess in increase of size & vigour. No doubt horticulturists, when they wish to raise new seedlings, often with pluck off all the flower-buds, except a few, or remove the whole during one season, so that the of a great stock of nutriment may be thrown into the flowers, which are to seed. No When plants are transported from high-lands, forests, marshes, heaths, into our gardens & greenhouses, there must be a considerable change of food, but it wd be hard to prove that there was in every case an excess of the kind proper to the plant. If it be an excess of food, how long the effects compared with that which the being obtained in its natural state, how the effects continue for

20v

(13G

a surprisingly an improbably long time; for during how many ages have has wheat been cultivated & cattle & sheep & dogs reclaimed; & yet they & we cannot suppose their amount of food has gone on increasing, nevertheless these are amongst the most variable of our domestic productions. It has been remarked that some of the highest fed most highly kept breeds of sheep & cattle are truer or less variable than the stra straggling animals of the poor, which subsist on commons, & pick up a bare subsistence. In the case of forest-trees, raised in nurseries, which vary it more, it is probable, than the same trees would in aboriginal forests, it seems to have the cause would seem simply to be, in their not having to struggle against other trees & weeds, which in their natural state doubtless would limit the conditions of their being able to rise from the seed. existence. It appears to me that the power of domestication renders itself into the accumulated effects of a change of all or some of the natural conditions of the life of the species, often associated with excess of food. These conditions, & moreover, I may add these conditions not remaining can seldom remain, owing to the mutability of the affairs, habits, migrations, & knowledge of man, for very long periods the same. I am the more inclined to think & come to the foregoing conclusion, from finding, as we shall hereafter show, that changes of the natural conditions of existence, seem peculiarly to affect the action of the reproductive system. As we see that hybrids & mongrels, after the first generation are apt to vary much, we may at least conclude, that variability does not at altogether depend on excess of food.—)

21

(13. H.

After these views, it may be asked, how it comes that certain animals & plants, which have been domesticated for a a considerable length of time, & transported from very different conditions of existence have not varied much, or scarcely at all; for instance, the ass, Peacock, Guinea fowl, asparagus, Jerusalem artichokes. I have already said, that probably different species, like different subvarieties, possess different degrees of tendency to vary; but I am much more inclined to the attribute the want of numerous races ofin thein these cases in many cases in great part less to want of variability, than to selection not having been practiced. No one will take the pains to select without some corresponding object either of use or amusement; he must be able to the ass & the cat have the individuals raised, must be thereby numerous, & not so precious, but what that he may freely destroy, those not answering to his wishes. If Guinea-fowls or Peacocks became "fancy" birds, I cannot doubt that after some generations several breeds would be raised. Asses have not been worked on for mere neglect; but they differ in some degree in different countries. The insensible selection, due to different races of man preserving in those individuals, most useful to them in their different circumstances, will apply only to the oldest & most widely domesticated animals. In the case of plants, we must put entirely out of the case those exclusively, (or almost so) propagated by cuttings, layers, tubers, such as the Jerusalem Artichoke & Laurel; & if we put on one side plants of little ornament or use; & those which are used at so early a period of their growth, that no especial characters signify, as asparagus & seakale, I believe, few can think of none long cultivated, which have not varied. In no case ought we to expect to find as much

22v

(13I

variation in a race, when only one race it alone has been formed, as when several have been formed, for their crossing & recrossing seems will greatly to increase their variability.

 

To sum up this chapter: Races are made under domestication,: 1st. by the direct effects of the external conditions, to which the they are exposed, on the entire stock species is all the species is exposed. on certain or on all the individuals are exposed: 2d. by means the indirect effects of the exposure to new conditions, often aided by excess of food, causing the offspring to vary in many ways, rendering the organization plastic, & by man's selecting & separately breeding certain individuals, or introducing to his stock selected males, or often preserving with care the life of the individuals best adapted to his purposes: 3d by crossing & recrossing races already made, & selecting their offspring. After some generations, man may in all the above cases relax his care in selection, for the tendency to vary & to revert to ancestral forms will decrease; so that he will have only occasionally to remove or destroy a few out of one of the yearly offspring which departs from its type. Ultimately with a large stock, the effects of free crossing would keep, even without this care, his breed pretty true. By these means, man can produce infinitely numerous races, most curiously adapted to ends, both most important & most frivolous; at the same time, that the effects of the surrounding conditions, the laws of inheritance, of growth, & of variation, will modify & limit his labours.

23

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Part Chapter to p 65 II

On The possible and probable application of the foregoing principle of Variation to organisms in a state of nature, and consequently on the possible and probable production of wild races, analogous to the domestic races of plants & animals.

On the variation of organic beings in a wild state;— on the natural means of selection;— and on the comparison of domestic races & true species.

 

(12) Organic beings in a state of nature vary exceedingly little: I put out of the case variations, (as stunted plants &c, & sea-shells in brackish water) which are directly the effect of external agencies, & which we do not know are in the breed, or are heredetary.— the amount of heredetary variation is very difficult to ascertain, because naturalists (partly from the want of knowledge, & partly i in the case of well known organisms from the inherent difficulty of the subject) do not all agree in whether certain forms are species or varieties races. (a)

Thus Botanists differ greatly from this cause alone on the relative proportion between the species & varieties of British Plants.— Lamarck [illeg] In many genera of insects & shells & plants it seems almost hopeless to establish which are which. In the higher classes there are less doubts; though we find quite considerable difficulty in ascertaining what are the deserve to be called species of amongst foxes & wolves; &— in some birds, for instance in the case of the white Barn-door owl, (B) Yarrell whether [illeg] on [illeg] find has remarked that the individuals of the same undoubted Europæan species of birds of from N. America & Europe oft usually present some slight indefinable though perceptible differences. The recognition indeed of one animal

23v

(B)

on the nat means of selection— the com On the var. of org in wild state of domestic races [illeg]

when specimens are brought from different parts of the world. How often do naturalists dispute, whether the same question, under similar circumstances, as I have observed, in specimens brought from the Galapagos islands.

(a). Some wild strongly-marked races of plants, comparable with the decided sports of horticulturists undoubtedly exist in the same country, as is actually known by experiment, for instance in the primrose & cowslip— in two so-called species of Dandelions, in two of foxglove, & I believe in some pines.— Lamarck has observed, that as long as we confine our attention to one limited country, there is seldom much difficulty in deciding what forms to call species & what varieties; & that it is when collections flow in from all parts of the world, that naturalists often feel at loss to divide the limit of variation. Yet amongst British plants, (& may add Land-shells) which are probably better known than any in the world, the best naturalists differ very greatly in the relative proportions of which they call species & what, varieties.

24

B) The disposition of wild animals undoubtedly differs. The varieties kn Variation, such as it is, chiefly especially affects the same parts in wild organisms as in domestic breeds as for instance the size, colouring colour & the external & less important parts.

24v

(15

by another seems to imply some difference. (B) In many species the variation variability of certain parts form as part of organs or qualities is given even stated as one of the Specific characters; thus the colour, in many is variable, whenwhilst it is fixed in others, size, hairiness, in plants the number of the stamens & pistils & even their presence — the form of the leaves, the size & form of the mandibles of the males of some insects, & the length & curvature of the beak in beak slightly so in others some birds (as Opetiorhyncus), are all fixed characters in some species & questionable in others. I do not perceive that any just distinction (?) can be drawn between this recognized variability of certain parts of certain organs in not a few many species, & the more general variability of the whole form frame in domestic organisms breeds races.)

 

(13) Although the amount of variation is be exceedingly small (& (perhaps next to nothing in some forms not more in some many animals, than sufficient to allow of recognition by each other) in most organisms beings in their a state of nature, & probably quite wanting, (as far as our senses serve) in the majority of cases; yet considering how long many animals & plants, taken from different quarters of the world, for the most diverse ends food use, amusement, & beauty have varied under domesticity, domestication in every country & in every age, I think we may safely conclude that it is the result of some very general law, & therefore that all most most existing organisms, if capable capable of being bred for long periods in domesticity under the dominion of man would vary.

 

(14) It has been seen, said (sect.3) that domesticity resolves itself into a change of the natural conditions; possibly often with an excess of food if so during the lapse of ages

25

(16

may safely conclude that all organic beings, with few exceptions, if capable of being domesticated & bred for long periods, would vary. As We have seen that Domestication seems to resolve itself into a change from the natural conditions of the species, generally perhaps including an increase of food; if this be so, organisms in a state of nature, would must occasionally in the course of ages be & exposed to analogous influences; for geology clearly shows that many places, must, in the course of ages time been exposed to the widest range of climactic & other influences; & if such places be isolated, so that new & better adapted organic beings cannot freely immigrate, the old inhabitants will be exposed to new influences, probably far more varied, than Man has applies under the form of domestication. Although every species no doubt will soon breed up to the full number, which the country will support, yet it is easy to conceive, that on an average some species may receive an increase of food, for the times of dearth may be recurrent only at long intervals. All such changes of conditions, from geological causes, would be exceedingly slow; what effect this slowness might have we are ignorant; under domestication, it appears that the its effects of external accumulate & then break out. Whatever might be the result of these slow geological changes,

26

Excess of food

26v

(16 a

most many wild organisms must be [illeg] occasionally exposed to analogous changes. Geology proclaims the possibility of each spot being exposed to every possible the widest range of climactic influences; & when the place is so circumscribed that organisms better adapted to the such changes cannot freely immigrate, the old inhabitants of will be exposed to new influences, for as wide & more more as various, than those which Man can apply under the form of domesticity. (A) Such geological changes, we have good reason to believe, supervene with exceeding slowness, this what influence this slow may have may possibly destroy the effects which otherwise would be produced, although under domesticity it appears the effect produced by a change of conditions, accumulate during several generations & at last break out. However this may be, we may feel sure, from the property means of dissemination common in a lesser or greater degree to every organism, taken conjointly with the changes of geography, which are steadily (& sometimes suddenly as when an isthmus at last separates) in progress, that occasionally an organisms will must suddenly be introduced into a country new regions, where if the conditions of existence are not so foreign as to cause its extermination, it will may will often be propagated under circumstances, still more closely apparently quite analogous to those of domestication; & therefore we might may expect will evince a tendency to

27

(17

vary. It appears to me inevitable almost certain that this must have quite inexplicable if this has never happened; but it can happen very rarely. Let us then suppose that Suppose an organism by some strange chance, (which might be hardly repeated in a 1000 years) to be arrives at one of a modern volcanic island of no great antiquity & in process of formation & not fully stocked with the most appropriate organisms, the new organism might readily gain a footing although the external conditions were considerably different from its native ones. The effect of this we might expect would influence in some small degree the size, colour, nature of covering, & i, and from inexplicable atmospheric influences even special parts & organs of the body. But we might further (& what is far more important) expect that the reproductive system would be as under domesticity be affected as under domesticity, & fail to transmit such exact likeness of the parent & be rendered plastic. and Hence that almost every part of the body would be occasionally be slightly altered tend to vary from the typical form in slight degrees & in no determinate way; & therefore that without selection, the free crossing of these small variations (together with the tendency to reversion to the original form) would constantly be counteracting this principle of variation unsettling effect of the extraneous conditions on the reproductive system.) would it

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(18

This I conceive would be the (15) t[illeg] unimportant result without selection; but let us suppose a Being with penetration sufficient to perceive differences in the outer & innermost organization, quite imperceptible to man & with forethought extending over future centuries, to watch with unerring care & sel select the for any object, the offspring there of an organism produced of under these foregoing circumstances; I can see no conceivable reason, why he could not form a new race (or several were he to separate the stock of the original organism & work on two several islands) adapted to some new ends. and, for instance if an animal to catch some new prey or, better to escape some new danger — if a plant to afford escape the ravages of some animal, or to grow in some new p station

like man selects greyhounds to improve their fleetness to catch hares. or their

As we assume his discrimination & his forethought & the period of his steadiness of object to be incomparably greater than that of man, so we may suppose the beauty of the & complications of the adaptations of the new races produced, & it's and their differences diversity from the parent original stock to be much greater than in the domestic races, produced by mans agency: His labours

28a

(18

Such, I conceive, would be the unimportant result without selection. And here I must observe that the foregoing remarks are equally applicable to that small & admitted amount of variation in some wild organisms in a state of nature, as well as to the hypothetical variation, consequent on changes of condition. Let us, now, suppose

[28a & 29v]

(18

Such, I conceive, would be the unimportant result without selection. And here I must observe that the foregoing remarks are equally applicable to that small & admitted amount of variation in some wild organisms in a state of nature, as well as to the hypothetical variation, consequent on changes of condition. Let us, now, suppose

 

a Being with penetration sufficient to perceive differences in the outer & innermost organization, quite imperceptible to man & with forethought extending over future centuries, to watch with unerring care & sel select the for any object, the offspring there of an organism produced of under these foregoing circumstances; I can see no conceivable reason, why he could not form a new race (or several were he to separate the stock of the original organism & work on two several islands) adapted to some new ends. and, for instance if an animal to catch some new prey or, better to escape some new danger — if a plant to afford escape the ravages of some animal, or to grow in some new p station

like man selects greyhounds to improve their fleetness to catch hares. or their

As we assume his discrimination & his forethought & the period of his steadiness of object to be incomparably greater than that of man, so we may suppose the beauty of the & complications of the adaptations of the new races produced, & it's and their differences diversity from the parent original stock to be much greater than in the domestic races, produced by mans agency: His labours

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(19

we may suppose The groundwork of his labours we may aid, by supposing, that the volcanic isld in arising external conditions of the volcanic isld from its emergence & the occasional introduction of new immigrants to vary; & thus occasionally to give unsettled slightly unsettled keep at intervals to act on the reproductive system of the organism, on which he is at work, at, & so keep the plan of its organization slightly unsettled. somewhat plastic. With time enough, such a being might rationally, (without some unknown law opposed him) aim at almost any result.)

(whether or no he would succeed it is another question)) ( for instance;— let him take a plant, which naturally grew on the soil, almost composed of rotten-fragments of in a thick wood on the ground, & let him wish to adapt give this plant to grow the means of growing on quite rotten partially decayed wood still [illeg] attached to the tree on the trunks of living trees, he might continue selecting the century after century every individual, whose seed-vessel be was ever so little larger, or & more fleshy (a tendency character which would generally be inherited) so as to be agreeable to a certain bird inhabiting frequenting the woods trees & on the other hand always destroying those which departed most from his desired end.; & this he might continue till (like man has made the sloe & crab large & pleasant to his taste), to do until the seed regularly formed part of — the regular food of this bird, & thus a large number were was regularly transported into the desired station. This workman might then

 

Begin with selecting the plants capable of living & then obtain dissemination.

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(20

For instance, let this imaginary Being wish, from seeing a plant growing on the decaying matter in a forest and choked by other plants in a forest, to give it power of growing on the rotten stems of trees, whi he would commence selecting every seedling, whose plant which had the slightest whose seeds berries were in the smallest degree more attractive to tree-frequenting birds so as to cause for their the a proper dissemination of the seeds & at the same time selecting those plants & which seedlings, which had the smallest slightest degree more & more power of drawing nutriment from rotten wood; He might thus, if the organization of the plant was at all plastic and destroying all others. He might thus, in the course of long time century after century hope to make the plant by degrees grow on rotten wood, even high up on trees, wherever birds dropped the non-digested seeds. He might then, if the organization of the plant was plastic, attempt by continued selection of chance-seedlings, to make it grow on less & less rotten wood, till it would grow on sound wood. Supposing, again, the during these changes the plant failed to seed quite as freely, from non-impregnation, he might begin selecting seedling seedlings with a little more or differently tasted pollen or honey or pollen or pollen to tempt insects to visit the flowers regularly: having effected this, he might wish, if it profited the plant, to also render abortive the stamens & pistils in different flowers, which he could do by continued selection. Such By such steps, he might aim at making a plant, as wonderfully related to other organic beings, as is the misseltoe, which could never produce a seed, without the intervention of certain insects, whose existence absolutely depends on certain insects for impregnation, certain birds for transportal, & certain trees for growth. Furthermore if the insect which had been induced regularly to visit this hypothetical plant, profited much by it, our same Being might wish by selection to modify by gradual selection the insect's structure

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(21

so as to facilitate its obtaining the honey or pollen: in this manner he might adapt the insect (always pre=supposing its organization to be in some degree plastic) the flower, &, & the impregnation of the flower to the insect, as is the case with many Bees & many plants.)

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(21a

the existence of certain insects, certain birds, & certain trees. I may further observe that if the organization of the insect which was gradually induced to visit regularly the more and more nectariferous one plant regularly the plant either for its pol nectar or pollen, was in the smallest degree plastic, the same workman might have modified selected modifications in the structure of its mouth or legs, & in that case the as the plant became adapted to the insect, the insect also would be to also become so to the plant, as is the case with many those Bees, whose limbs are formed to carry pollen & those plants whose impregnation depends on these insects.—

 

(16) (Seeing what blind capricious man has actually effected by selection the few last years & what in a ruder state he has probably effected [illeg] without any systematic plan during the last few thousand years, he will be a bold person, who will positively put limits to what a the supposed hypothetical Being could effect during whole geological periods. In accordance with the plan by which this universe seems governed by the Creator, let us consider whether there exist any secondary means means in the œconomy of nature, by which this selection the process of selection could go on, adapting nicely & wonderfully adapting organisms if in ever so small a degree & o plastic to diverse ends. I believe such a secondary means do exist.)

[previous two repeated]

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(22

(17) Decandoelle in an eloquent passage has declared that all nature is at in constant war, one organism with another, or with external nature. Seeing the contented face of nature on a bright summer's day this may at first be well doubted; but reflection will inevitably prove it is too true. The war,, however, is not constant, but only recurrent in a slight degree at short periods & more severely at occasional longer ones more distant periods, & hence its effects are easily overlooked. It is the doctrine of Malthus applied in most cases with ten-fold force. As in every climate there are seasons for each of its inhabitants of greater & less abundance, so all annually breed; & the Moral restraint, which in some small degree checks the increase of mankind is entirely lost. Even slow-breeding man-kind has doubled in 25 years, & if he could increase his food with greater ease, he would double in less time. But for animals without arts, On an average, the amount of food for each species must be constant; whereas the increase of all organisms (if not destroyed) is tends to be geometrical & in a vast majority of cases at an enormous ratio. Suppose in a certain spot there are ten eight pair of Robins, & that only five four pair of them annually rear including double hatches rear their say four only four young, & that these go on rearing their young at the same rate; then at the end of eight seven years ( a short natural life excluding violent deaths for a robin), if there will be 2048 robins, instead of the original sixteen; as this increase is quite impossible, so we must conclude either that Robins do not rear nearly half their young. or that the average life of a Robin when reared is from accidents not nearly eight seven years. Both checks probably concur. The same kind of calculation with applied to all vegetables & animals produces far more striking result either less results either more or less striking, but in scarcely a single one case instance, less than in man) but generally far more striking results. than in man.)

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(23

(Many practical illustrations of this rapid tendency to increase are on record, namely during peculiar seasons, in the extraordinary increase of certain animals, for instance during the year 1826 to 28, in La Plata when from drought some million cattle on perished, the whole country swarmed with innumerable mice: now I think it cannot be doubted that during the breeding season all the the mice (with the exception of a few males or females in excess) the mice ordinarily pair, & therefore this astounding increase during these years can only must be attributed to a greater portion than usual number surviving the first year of the drought, & these breeding & so, till the third year, when their numbers were brought down to their usual limits, on the return of wet weather again. Where man has introduced an organism plants & animals into a new country, favourable to its, them, there are many accounts of in how surprisingly few years, the whole country has become stocked with them; nevertheless This increase would necessarily stop as soon as the country was fully stocked, & yet we have re every reason to believe from what is known of wild animals, that all would pair in the Spring. In the majority of cases it is most difficult to imagine where the check falls, generally no doubt on the young & seeds, eggs, & young; but when we remember how impossible even in mankind (so much better known than any other animal) it is to infer from repeated casual observations, what the average of life is, or to discover how different the percentage of death to the population in different countries, we ought to feel no legitimate surprise at not seeing where the check falls in animals & plants. It should always be remembered that in most cases the checks are yearly recurrent in seasons in a small regular degree; & in an extreme degree by the year occasionally & during unusually cold, hot, dry or

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wet years, (according to the constitution of the being organisms in question). As eve Lighten these any check in the smallest degree, & the geometrical power of increase present in every organism will instantly increase the average numbers of the favored species. Nature may be compared to a surface, on which rest ten-thousand sharp wedges touching each other & driven inwards by incessant blows. Fully to realize these views, much reflection is requisite; study Malthus on man should be studied; and consider the case of a savage country, & reflect of the enormous power of multiplication from recorded all such cases, (as that those of the mice in Rio R the La Plata, of the cattle & horses when first turned out in S. America, of the Robins by our calculation &c,) should be well considered; reflect on the enormous multiplying power inherent & annually in action in all animals; reflect on the countless seeds scattered by a hundred ingenious contrivances, year after year, over the whole face of the country land;— & yet we have every reason to suppose that the average percentage of every one of its organisms the inhabitants of a country will ordinarily remain constant. we know if a forest is cut down, though weeds & different trees will at first spring up, that the old proportion will in centuries establish themselves. Every form continues steadily is struggling to increase, but the struggle is result must be soon decided, & without external changes, the proportion of the inhabitants will must remain constant. Finally let it be borne in mind that this average number of individuals (the external conditions remaining the same) in each country is kept

(18) up by a cons recurrent struggles against other species or against external nature (as on the borders of the art arctic regions, where the cold checks life); & that ordinarily each individual of each species holds its own place either by its own struggle & capacity of acquiring nourishment food in some period (, from the egg upwards, or periods of its life, or by the struggle of its

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parents (in cases short-lived organisms where the main check occurs at longest long intervals), against & compared with other individuals of the same or different species.—)

 

(18) (But let the external conditions of a country change; if in a very small degree, the relative proportions of the inhabitants organisms in most countries will in most cases simply be slightly be changed; but let the number of inhabitants be small as on an island, & free access to it from other countries be circumscribed; & let the change of conditions continue progressing, forming first new stations, the original inhabitants will must cease being be so perfectly adapted to the changed conditions, as they originally were. we m all appearances show they are adapted in old countries. It has been shown that probably the such changes of external conditions, would from acting on the reproductive system, indu cause the form of those organisms, which were organization of the beings most affected by the change in question to vary. to become, as under domestication, plastic. How can it be doubted, that from the struggle each individual has (or its parents) has to obtain existence subsistence, that if any, minute variation in form in structure, habits & instincts adapting that organism individual better to the new conditions, would be tell upon the its vigour & health. of that individual. In the struggle, it would have a better chance of surviving, & those of its offspring which inherited the variation, let it be ever so small slight, would have a better chance to survive. Yearly more are bred than can survive; the smallest grain in the balance in the long run must tell on which death shall fall, & which shall survive. Let this work of selection

37v

(a) The great bar to diffusion, viz preoccupation wd here be best

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on the one hand, & death on the other, go on, for a thousand generations, who will pretend to deny it created affirm that it would produce no effect, when we remember what in a few years Bakewell effected in cattle & Western in sheep by this identical principle of selection. To give an imaginary example let the organization, from changes in progress on an island, let the organization of a canine animal become slightly plastic, which animal preyed chiefly on rabbits, but sometimes catching a on hares; let these same changes cause the number of rabbits very slowly but steadily to decrease & the number of hares to increase; the effect of this wd be that the fox or dog wd be driven to try to catch more hares, & his number wd tend to decrease; his organization however, being slightly plastic, those individuals with the lightest lightest forms, longest limbs & best eyesight, (though perhaps with less cunning or scent), let the difference be ever so small, and individuals would in the course of be slightly favoured, & would tend to live longer, & to rear more young & to survive during that time of year, when food was shortest, they would also rear more young, which young would tend to inherit these slight peculiarities. The less fleet ones wd be rigidly destroyed. I can see no more reason to doubt but that these causes in a thousand generations would produce an a marked effect & adapt the form of the fox to chasin catching hares instead of rabbits, than that greyhounds can be improved by selection and careful breeding. So would it be with plants having a somewhat plastic organization under similar circumstances; if the number of individuals of a species with plumed seeds could be increased by greater powers of dissemination, that is if the check to increase fell chiefly on the seeds; those seeds, which were provided with ever so little more down or with down plume placed so as to be slightly more acted on by the winds, would on the long run tend to be most disseminated; would & & hence a greater number of seeds thus formed would germinate & would tend to [illeg] produce plants inheriting this slightly better adapted down.)

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(19)

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Besides this natural means of selection, by which those individuals, whether in their egg or seed, or in their mature state, which are best adapted to the place they fill in nature, are presented; there is a second agency at work, amo producing in most bisexual animals tending to produce the same effect, namely the struggle of the males for the females. These struggles are generally decided by the law of battle, but in the case of birds, apparently by the charms of their song, their beauty, or their power of courtship, (as in the dancing rock-thrush thrust of Guyana. &c). (B)

The most vigorous & healthy males implying perfect adaptation, must generally gain the victory in these several contests. A.A.

In a somewhat analogous manner, those females, which are most healthy, capable of obtaining most food & escaping their enemies, must rear most young. This kind of selection, however, is less rigorous than the other; it does not require the death of the less successful, but simply fewer gives to them fewer descendants. This struggle falls, moreover, at a time of year when food is generally most abundant & perhaps the effect chiefly produced would be the production alteration of sexual characters & the selection of individuals form, individual forms, no way related to their powers of obtaining food, but of f or of defending themselves from their natural enemies, but of fighting one with another. This natural struggle amongst the males may be compared in effect but in a less degree to that produced by mankind favour,, by those agriculturists who pay less attention to the careful selection of all the young animals which they breed, & more to the

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(B.) Even in the animals which pair there seem to be an excess of males which wd aid in causing a struggle: (In in the polygamous animals, however, (as in Deer, oxen, Poultry,) we might expect there wd be severest struggle: —) is it not in the polygamous animals that the males are best formed for mutual war?

 

A.A.

{Had better be introduced as the ordinary section of Selection — as it applies to more cases & the less successful happy young

it is selection falling perish..— —

on the young, not for their own lesser power or adaptation, but from their parents lesser power & adaptation.—

40

occasional use of a choice male.

 

 (20.)Supposing races to be thus formed by natural means, let us compare their probable characters with

The races can be adapted to various ends & differing in structure, are formed by these natural means of selection, acting on the small variations arising from in the form of wild organisms, it is it is obvious obvious they are what are called species. Species differ from acknowledged races in one or more The only criteria which can be pointed out, between species & races (without we beg the question & affirm that the character of the difference of a of species consist in their not having descended from common parents) consists in the less variation of forms, the greater uniformity in character of species & in their frequent sterility or in the sterility of their hybrid offspring.

(A) A) By He is unable to select shades of diffe constitutional differences & by the protection he affords & thus his endeavors to keep his pr property alive, in whatever country he lives; he prevents checks, as much as lies in his power, the selecting action of nature, which must will, however, go on to a lesser degree with amongst all living things, in domesticity wherever his every creatures live, even if their length of life is not determined by their own powers of endurance.

(B) He often does seldom allows the most vigorous males to struggle for themselves & propagate themselves; but picks out such, as he has, possesses, or such as he prefers, or wishes, & not necessarily those best adapted to the these existing conditions

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occasional use of a choice male.

 

(20) (Races produced by these  foregoing natural means of selection, we may expect would differ in some respects from those made produced by man. Man selects chiefly by the eye & is not able to perceive the course of every vessel & nerve or the form of the bones, or whether the internal structure corresponds to the outside shape (A) .— He has bad judgement; is capricious;— he does not wish & indee. nor or his successors do not wish to select for the same exact end for many hundreds of generations. He does can not always suit the selected form to the properest condition; — nor can does he keep those conditions uniform: he selects that which is useful to him, not that best adapted to the conditions he presents to the organism, he is working at: he selects a small dog, but feeds it highly; he selects a long-backed dog & does not exercise it in any peculiar manner, at least not during every generations.— (B) Every agriculturist & breeder knows how difficult it is to prevent an occasional cross with some another breed.— He often grudges to destroy an individual which departs considerably from the required type. He often begins his selection by a form or sport, considerably departing from the parent form. Very differently does the natural act law of selection act:— the varieties selected differ only slightly from the parent-forms; for smaller the conditions are constant or nearly so for long periods & change slowly; rarely can there be a cross; the selection is rigid & unfailing, & continued through many generations;— a selection can never be made without the form be better adapted to the new conditions, than the parent parent form;— to these

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adopting the forms to their conditions; the selecting power, without caprice, & steadily for thousands of years continues to act. adapt the forms to their conditions. The selecting power, is not deceived by external appearances; it trys the animal being during its whole life, & if less well adapted than its congeners congeners, of without fail it is destroyed; every part of its structure is thus scrutinized & proved proved good toward the desired end. place it occupies. We have every reason to believe that in proportion to the number of generations that as a domestic race is kept 'true' by avoiding free from crosses & to the care employed in by continued steady selection with one end in view & in not placing the organism variety in conditions unsuited to it; in that such proportion does the new race become 'true' or subject to less little variation. How incomparably 'truer', then, would a race be produced by the above rigid, steady natural means of selection, well excellently trained & well excellently adapted to its conditions, free from stains of blood or crosses, & continued during thousands of years, be compared with one produced by the feeble, often, capricious, misdirected & ill adapted power selection of man. (A) Now the characteristic mark of species next if not equal in importance to their its sterility of species when coupled with another species; & indeed almost the only one other character (without we beg the question & affirm the essence of a species is, its not having descended from a common parent common to any other form) is the [illeg] similarity of the individuals composing it, or in the language of agriculturists their 'trueness'.—

41v

Those races of domestic animals, produced by savages, (A) wh partly inevitably by the partly by the inevitable conditions of their life & partly unintentionally by their greater care of the more valuable individuals most valuable to them, & which savages have no other breeds of the same species would probably approach closest to the character of a species; as I believe is the case.

42

(A)It will be naturally  objected to asked on the view, that species are varieties selected by the natural process as above explained; why should they when coupled together be often sterile? often produce sterile offspring?

(A) I must, however, remark that the fact whether one species will or will not breed with another is far less important in any [illeg] than the sterility of the offspring when produced; for even even some races, even differ so greatly in size, (as the great stag-greyhound & lap-dog; or cart-horse & Burmese ponies) that union is nearly impossible; & what is less generally known, is, that in plants Koelereuter has shown by hundreds of experiments that the male of one pollen of one species will fecundate the pistil germen of another species, whereas the pollen of the latter will never act on the st pistil germen of another the former; so that the union to according to the sexes as far as mutual impregnation serves as a test of distinct species, according as one or the other sex is taken, the test fails or serves. But there exists a perfect gradation in fertility in the results from intercrossing, when union has been effected;

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(21) The Sterility of species, wh when crossed, or of their offspring had from them, when crossed, has, however, acquired received more attention than the uniformity in character of their individuals composing the species. (A) It is exceedingly natural that such sterility should have been long thought the certain characteristic of species. For it is obvious, that if the allied different forms which we meet with in the same country could cross together, instead of finding a number of distinct species, we shd have a confused & blending series; as, therefore, the sterility is necessary in most cases to preserve species, it was natural it shd be thought an their absolute character. The fact, however, of a perfect gradation in the degree of sterility between allied species, & the circumstance of some species, most closely allied, for instance the many species of crocus &Europæan Heaths, refusing to breed together, whereas other species widely different & even belonging to distinct genera; as the fowl & Peacock, azalea & Rhododendron, readilybreeding together & in the case of the pheasant & grouse breeding so readily as frequently to cross in the wild state, might ought to have caused a doubt, whether the sterility d did not depend on other causes, distinct from some a law, coincident with their creation. (A) If such a law had been enforced to keep species distinct & was their characteristic mark, it would be strange that The A perfect gradation of in sterility is clearly marked: union is physically impossible between forms greatly remote; but as the species, experimented on come closer, [illeg] when the difference is less, great

43

admission, that in certain families the hybrid offspring of two many of the species, are sometimes perfectly fertile in the first generation, when bred together: indeed in some few cases Mr Herbert found that the hybrids were decidedly more fertile, than either of their pure parents. There is no way to escape from the admission that the hybrids from some species of plants are fertile; except by declaring that no forms should be considered as a species, if it produces with another form, fertile offspring: but this is begging the

44

question. It has of-ten been stated, that different species of animals have a sexual repugnance towards each other; I can find no evidence of this; it appears as if they merely did not excite each others passions. & I do not believe that in this respect there is any essential distinction in this respect between animals & plants; and in which the latter there cannot be repugnance. We

[page in the hand of Ebenezer Norman with corrections by Darwin]

45

This difference in nature between species, which causes the greater or lesser degree of sterility in their offspring, appears, according to Herbert & Koelreuter, to be connected, much less with external form, size or structure, than with constitutional peculiarities; by which is meant, their adaptation to different climates, food, & situations &c: such these peculiarities of constitution we must suppose probably affect the entire frame, & no one part in particular.)

 

(From the foregoing facts, I think we must admit, that there exists a perfect gradation in sterility fertility between species, which when crossed are

[43-45]

admission, that in certain families the hybrid offspring of two many of the species, are sometimes perfectly fertile in the first generation, when bred together: indeed in some few cases Mr Herbert found that the hybrids were decidedly more fertile, than either of their pure parents. There is no way to escape from the admission that the hybrids from some species of plants are fertile; except by declaring that no forms should be considered as a species, if it produces with another form, fertile offspring: but this is begging the

question. It

question. It has of-ten been stated, that different species of animals have a sexual repugnance towards each other; I can find no evidence of this; it appears as if they merely did not excite each others passions. & I do not believe that in this respect there is any essential distinction in this respect between animals & plants; and in which the latter there cannot be repugnance. We

This difference in nature between species, which causes the greater or lesser degree of sterility in their offspring, appears, according to Herbert & Koelreuter, to be connected, much less with external form, size or structure, than with constitutional peculiarities; by which is meant, their adaptation to different climates, food, & situations &c: such these peculiarities of constitution we must suppose probably affect the entire frame, & no one part in particular.)

 

(From the foregoing facts, I think we must admit, that there exists a perfect gradation in sterility fertility between species, which when crossed are

46v

quite fertile (as in Rhododendron, Calcerlaria) Calceolaria &c) & indeed in an extra-ordinary degree fertile (as in Crinium Crinum) when crossed to and those species which will not never produce offspring, but yet which by certain effects, (as the exsertion of the pollen-tube) evince their alliance. & lastly to those whose reproductive system no way influence each other. Hence I conceive we must give up sterility, although undoubtedly in a lesser or greater degree of very frequent occurence, as an unfailing mark by which species can be distinguished from races, i.e. from those forms which have descended from a common stock.)

 

(Let us see whether there are any analogical facts, which will throw any light on this subject, & will tend to explain why the offspring of certain species, when crossed, should be sterile, & not others; without

[page in the hand of Ebenezer Norman with corrections by Darwin]

47

31f

When two species are attempted to be crossed, which are so distantly allied, that offspring are never produced, yet it has been observed in some cases, that when attempted to be crossed the pollen commences its proper action by exserting its tube, & thus germen commences swelling, though no result soon afterwards it decays. When hybrid-offspring are produced In the next stage in the series, hybrid-offspring are produced, though only rarely & few in numbers, & these are absolutely sterile: then we have hybrid-offspring more numerous & occasionally, though very rarely, breeding with either parent, as is the case with the common mule. Again other hybrids though infertile together inter se (as the will breed quite freely with either parent, or with a third species, & will yield offspring generally infertile, but sometimes fertile; & these latter again will breed with either parent or with a third or fourth species: thus Koelreuter blended together many forms. Lastly, it is now admitted by those botanists, who have longest contended against the

48

31(a)

(52

the sterility did not depend on other causes, distinct from a law, coincident with their creation. I must, however, may, here remark that the fact whether one species will or will not breed with another, is far less important than the sterility of the offspring when produced; for even some domestic races, differ so greatly in size, (as the great stag-greyhound & lap-dog; or cart-horse and Burmese ponies) that union is nearly impossible; & what is less generally known, is, that in plants Koelerenter has shown by hundreds of experiments, that the pollen of one species will fecundate the germen of either another species, whereas the pollen of this latter, will never act on the germen of the former; so that as far as the simple fact of mutual impregnation serves as a test certainly has no relation whatever to the distinctness in creation of the two forms.

[illeg] distinct species, according as one or the other sex is taken, [text damaged]

[illeg] fails or serves. But there exists When two forms can be crossed, there exists results, as I have said, a perfect gradation in fer-

[illeg] ility in of the results from intercrossing, when union has been effected; offspring, thus produced:

it has even been observed, in plants, that though no seeds are

produced, the pollen seems aware that it is placed on the stigma

of a congenerous species & excerts its tube, & the ovule in other cases

swells, but does not properly germinate. In the next stage, hybrid

offspring are occasionally produced but few in number, & absolutely sterile; or they

[illeg] more numerous, & will very rarely produce with one of their

[page in the hand of Ebenezer Norman with corrections by Darwin]

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31(a)

(52

the sterility did not depend on other causes, distinct from a law, coincident with their creation. I must, however, may, here remark that the fact whether one species will or will not breed with another, is far less important than the sterility of the offspring when produced; for even some domestic races, differ so greatly in size, (as the great stag-greyhound & lap-dog; or cart-horse and Burmese ponies) that union is nearly impossible; & what is less generally known, is, that in plants Koelerenter has shown by hundreds of experiments, that the pollen of one species will fecundate the germen of either another species, whereas the pollen of this latter, will never act on the germen of the former; so that as far as the simple fact of mutual impregnation serves as a test certainly has no relation whatever to the distinctness in creation of the two forms.

[attached insert:] When two species are attempted to be crossed, which are so distantly allied, that offspring are never produced, yet it has been observed in some cases, that when attempted to be crossed the pollen commences its proper action by exserting its tube, & thus germen commences swelling, though no result soon afterwards it decays. When hybrid-offspring are produced In the next stage in the series, hybrid-offspring are produced, though only rarely & few in numbers, & these are absolutely sterile: then we have hybrid-offspring more numerous & occasionally, though very rarely, breeding with either parent, as is the case with the common mule. Again other hybrids though infertile together inter se (as the will breed quite freely with either parent, or with a third species, & will yield offspring generally infertile, but sometimes fertile; & these latter again will breed with either parent or with a third or fourth species: thus Koelreuter blended together many forms. Lastly, it is now admitted by those botanists, who have longest contended against the

[page in the hand of Ebenezer Norman with corrections by Darwin]

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gradation from species quite (as in Rhododendron Crinium Calceolaria) & indeed in an extra-ordinary degree fertile (as in Crinium) when crossed, to those which will not produce offspring, but yet which by certain effects, (as the exserion of the pollen-tube) evince their alliance, & lastly to those whose organs of reproduction which whose reproductive systems no way influence each other. I may add that in the according to the reasoning of several naturalists, which I think carries with it considerable probability, most of our domestic animal, viz, horses, cattle pigs, dogs & pigeons &c have descended from the blending together of fertile crosses of several wild aboriginal forms,

Hence, I conceive we must give up sterility, although undoubtedly in a lesser or greater degree of very frequent occurrence, as an unfailing mark by which species can be distinguished from races, which are known have descended from a common stock.)

 

(22) (Let us see whether there are any analogical facts why which will throw any light on this fact that circumstance why certain species, [illeg] & offer any explanation subject & will explain tend to explain X (without requiring conditional laws to that effect) X why the offspring of certain species when crossed shd be sterile together when crossed & not others, without requiring a distinct law connected with their creation to that effect. Great numbers, probably a large majority of animals, when taken from caught by man & removed from their natural conditions, although taken very young, rendered quite tame, living to a good old q age, & apparently quite healthy, seem

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quite incapable under the circumstances of breeding. I do not refer to animals kept in menageries, such as at the Zoological gardens (many, however, of which appear healthy & live long & unite but do not produce nothing); but to animals caught and left partly at liberty in their native country. Rengger enumerates several caught young & rendered tame in this case which he kept in Paraguay, which would not breed: the Hunting cat leopard or Chetah & Elephant offer other instances; as have Bears in Europe, & the 25 species of hawks, belonging to different genera, preserve which thousands of which have been kept for hawking & have lived for great long periods in perfect vigour. When the expence & trouble of procuring a succession of young animals in a wild state be borne in mind, one may feel sure that no trouble has been spared in endeavoring to make them breed. So clearly marked is this difference in animals different kinds of animals, when taken by man that St. Hilaire makes two great classes of animals useful to man;— the tame which will not breed, & the domestic which will breed in domesticity. domestication. From certain singular facts, we might have supposed, that the non-breeding of animals was owing to some perversion of instinct. But we meet with exactly the same class of facts in plants: I do not refer to the large class of facts number of cases, where the climate does not permit the seed or fruit to ripen, but where the flowers do not "set", owing to some imperfection of the ovule or pollen. The latter, which alone can be distinctly examined, is often manifestly imperfect, which as anyone with a microscope can observe by comparing the pollen of the Persian & Chinese lilacs

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(A) according to agriculturists, slight changes of conditions, that is of food or situati habitation, and likewise crosses with races slightly different increase the vigor, & probably the fertility of their productions. It would appear also that even a great change of condition, for instance transportal from temperate countries to India, in many cases does not in the least affect the fertility, although it does health & length of life, & period of maturity. When sterility is induced by domestication it is of the same kind, & varies in degree, exactly as with hybrids:

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with the common lilac: the two forms, I may add, are equally sterile in Italy as here, in this country. The Many of the American bog-plants here produce no little or no pollen in Britain, whilst the Indian species of the same genera freely produce it. In the exotic Geranium the deficiency of pollen seems connected with the period when water is given them; in no other instance can cultivators guess the cause.— Lindley stat observes that sterility is the bane of the Horticulturist: Linnæus has remarked on the sterility of nearly all alpine flowers when cultivated in a lowland district. Perhaps the immense class of double-flowers chiefly owe their structure to an excess of food acting on parts rendered slightly sterile & less capable of performing their true function, & therefore liable to be rendered monstrous; which monstrosity, like any other disease is inherited. So far from domestication being in itself unfavourable to fertility, that it is proverbial, well known, when an organism submits or is once capable of submission to these such conditions, their fertility is greatly increased beyond the natural amount limit. (A); for be it remembered that the most sterile hybrid is no ways monstrous; its organs are perfect, but they do not act, and minute microscopical investigations show, that they are in the same state, as those of purl pure species in the intervals of the breeding season. The defective pollen, in the cases above alluded to, precisely resembles that

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pollen of hybrids. The occasional breeding of hybrids, as of the common mule, may be aptly compared to the most rare, but occasional birth of re production of young elephants in captivity. The cause of many exotic geraniums producing although in vigorous health imperfect pollen, seems to be connected with the period when water is given them; but in the far greater majority of cases, we can not form any conjecture on what exact cause the sterlility of organisms, taken from their wild natural conditions, depends. Why, for instance the chetah will not breed, whilst the ferret & common cat & ferret (this latter generally kept shut up in a small box) do,— why the elephant will not, whilst the pig will abundantly— why the partridge & grouse in their own country will not, whilst some species of pheasants, the guinea-fowl from the deserts of Africa, & the peacock from the jungle of India will. We must, however, feel convinced that it is owing is depends on some constitutional peculiarities in these beings, not suited to their new conditions; though not necessarily connected with their causing an ill state of health. Can Ought we then to wonder much, that those hybrids, which have been produced by the crossing of species, with different constitutional tendencies, (which tendencies we know to be eminently inheritable) should be sterile: it does not seem improbable that the cross ing an from an alpine & lowland plant & shd have its constitutional adaptive powers deranged, whether made to grow in a lowland or highland locality, in nearly the same way manner as when the parent alpine plant is brought down into a lowland district. Analogy, however, is a deceitful guide, & it would be rash to st believe affirm, although it may appear probable, that the sterility of certain these hybrids which cannot breed, is is so closely similar to

53v

is absolute due to the constitutional peculiarities adaptations peculiarities of one parent being not suited to disturbed by being blended with those of the other parent, in exactly the same manner, as the it is caused in those some organic beings, which are when placed by man out of their natural conditions.

constitutional peculiarities of so many organisms sterility of man so many organisms, which are placed certain organic beings, those when taken by man, is superinduced, by their constitutional peculiarities being disturbed from being placed out of their natural conditions;— are disturbed without in either case their general state of health being affected. Although this might be rash, it would, I think, be still rasher to assert, that the sterility, when present, of certain in hybrids made by the arts of man, between any two species was connected with the laws of the proved their distinct creation, whilst we see that the art of man renders superinduces on certain animals, a sterility of the same kind

sterility of the same nature kind is superinduced in certain species & not in others by causes wholly noways unconnected with the distinctness of their creation.

sterility of a similar kind is superinduced on one species, by the same causes which renders do not affect another species more fertile, both species having equal claims to distinct creation.

 

(23) (But it may be objected, however little the sterility of certain hybrids is connected with the distinct creations of their parents, of species, how comes it, that the if species are only races produced by natural selection, or species, are so commonly sterile, that when crosssed they so frequently produce sterile offspring, whereas between in the offspring of in those races

54v

Although this might would be rash, it would, I think, be still rasher, seeing that sterility is no more incidental to all hybrids, than it is to all organic beings when taken captured by man, to assert that the sterility of certain hybrids we proved, is was connected with a distinct creation of their parents.)

[53v-54v]

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is absolute due to the constitutional peculiarities adaptations peculiarities of one parent being not suited to disturbed by being blended with those of the other parent, in exactly the same manner, as the it is caused in those some organic beings, which are when placed by man out of their natural conditions.

constitutional peculiarities of so many organisms sterility of man so many organisms, which are placed certain organic beings, those when taken by man, is superinduced, by their constitutional peculiarities

[pinned insert:] Although this might would be rash, it would, I think, be still rasher, seeing that sterility is no more incidental to all hybrids, than it is to all organic beings when taken captured by man, to assert that the sterility of certain hybrids we proved, is was connected with a distinct creation of their parents.)

art of man renders superinduces on certain animals, a sterility of the same kind

sterility of the same nature kind is superinduced in certain species & not in others by causes wholly noways unconnected with the distinctness of their creation.

sterility of a similar kind is superinduced on one species, by the same causes which renders do not affect another species more fertile, both species having equal claims to distinct creation.

 

(23) (But it may be objected, however little the sterility of certain hybrids is connected with the distinct creations of their parents, of species, how comes it, that the if species are only races produced by natural selection, or species, are so commonly sterile, that when crosssed they so frequently produce sterile offspring, whereas between in the offspring of in those races

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& confessedly produced by the arts of man, there is no one instance of sterility. There is not much little difficulty on this; for on the most probable supposition of Herbert & Kolreuter, which seems to the most probable one that those species alone produce sterile offspring, whose constit difficulty in this, for the races produced by the the natural laws of selection are means, above explained will be slowly but steadily selected; slowly, will be adapted to various & diverse conditions,, & to these conditions they will be rigidly confined for immense periods of time; here we may suppose that they will naturally be possessed of would acquire different constitutional, peculiarities adapted to the end they stations they occupy; & on which the constitutional differences between species, we have the probability of their sterility according to the best authorities probably depends.— On the other hand, man selects by external appearance (A) &; from the value he attaches, to each individual he exerts his utmost power in contravening the natural tendency of the most vigorous to survive— Man, moreover, especially in the earlier ages, cannot have kept his conditions constant & in later ages his stock pure. Until man takes selects two varieties from the same stock, best adapted to two climates or to other such different external conditions differences, & confines them each rigidly for one or several thousand years to these ends such conditions, always selecting the individuals best adapted to them, he cannot be said to have tried even commenced the experiment. Moreover the organic beings, which man has longest had under domesticity domestication, which were of of the greatest

55v

(A)

;from his ignorance & from not having any test so nice as the at least comparable in delicacy, to the natural occasional struggle for food continued on occasions at intervals in a wild state throughout the life of each individual, he cannot eliminate fine shades of constitution, dependent on invisible differences in the fluids or solids of the body;—

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[sketch]

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use of to him; & one chief element of their usefulness, especially in the earlier ages, was must have been their capacity to undergo sudden transportal into various climates & at the same time to retain their fertility which in itself implies that in such respects their constitutional peculiarities were not much closely limited. If the opinion already mentioned, of several naturalists be correct,, that most of the domestic animals in their present state, have descended from the fertile commixture of wild races that is or fertile species, we have so less indeed little reason now to expect infertility between any late cross of thus stock thus descended.) .⁋.

 

(24)It is worthy of remark that, as shown in the First  Part Chapter of this work, a tendency to vary seems to be the effect of the parents being placed by domestication out of. cond their natural conditions, that is being domesticated;

 

when organic beings are [illeg] by man & breeds for several generations under his dominion, the offspring vary exceedingly to a extent & decline, which seems to imply that the reproductive system is affected, and as we have seen, thus when some organic beings are taken by man, they [illeg] an excess of breeding

 

moreover that this tendency seems to result from the new or varying conditions having some peculiar action on the reproductive system, rendering the organization of the offspring in some degree plastic. for the varieties produced cannot be considered from reasons before given as the direct effect of the such conditions, by which their its power to transmit exact likenesses of the parents seems, as before expressed, in some degree to fail. Now we have just seen that in other cases, (in which we may suppose the external conditions are more different from the natural ones) that the reproductive system ceases entirely fails to act & the individuals are as sterile, as the most hybrids sterile offspring of the resultant crossed species;— a sterility

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(It is worthy of remark, that, as we as many organic beings, when taken by man out of their natural conditions have their reproductive sytem so affected, as to be incapable of propagation, so, we saw in the First Chapter, that although other organic beings when taken by man do propagate freely, but that their offspring after some generations vary or sport to a degree, which can only be explained by their reproductive system being someway affected. (A)

Moreover this varying or 'sporting' seems to come on, when the being has been bred for some generations under captivity, and it was found by Koelreuter that when resul hybrids by crossing with either parent or with other species are made to breed for some generations, they vary in a excessive degree. All Agriculturists likewise affirm, that after the first generation the same thing, with respect to mongrels, The after the first generation. The connection between these facts may be accidental, but they certainly appear to elucidate & support each other, on the principle of the reproductive system of all organic beings being eminently sensitive to any disturbance whether from removal or commixture in their constitutional relations between the constitution the of the species & the conditions to which they may are exposed.—)

 

whether from the individual being taken by man from their its natural state, or from the commixture of species and races.

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(A) Again we have seen that when species cross, their offspring are generally sterile; & but it was found by Koelreuter, that when the hybrids -offspring & its are capable of breeding with either parent or with other species, that they their offspring are subject after some generations to excessive variation. Moreover Agriculturists, also, affirm that the offspring from mongrels, when after the first generation vary much. So that we find Hence we see that sterility or variation of the [illeg] kind, in the succeeding successive generations, are consequent both on the removal of individual species from their natural states & from on two species having crossing.

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(A). I may recall a former statement, that Breeders believe the growth of one part or strong action of one one function, draws now causes a decrease in other parts; for this seems analagous to the law of "organic compensation", which most naturalists believe holds good, with some exceptions; for instance, where th in those species of Carnivora, in which the canine teeth are greatly developed, certain molar teeth are deficient; or again in that division of the Crustaceans in which the tail is much developed, the body is little so & the carcase.

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although Races descended from a common parent & reputed species agree in some respects, although they differ in their fertility when crossed & in their 'trueness', but from causes which we can in some degree understand. yet In the first place, there is no evident marks clear signs by which to distinguish races from species, as is evident from the great differences amongst naturalists to discriminate them. As far as external characters are concerned, many races probably descended from the same stock differ far more than true species of the same genus;— look at the willow-wrens, some of which the skilful ornithologists can hardly distinguish from each other, except by their nests; look at the wild swans, & compare these distinct species with the races of domestic ducks,— the Dorking & Bantam fowls, the dogs, several pigeons— and so again with plants compare the cabbages, peaches & nectarines, or with the species of many genera. — St. Hilaire has even remarked that there is a greater difference in size between races, as in dogs, (for he believes all have descended from one stock) than between the species of any one genus; nor is this surprising considering that amount of food & consequently growth is the element of change, over which man has most power. (A) The variation or difference between races is often strikingly analagous to that between species of the same genus; trifling spots or marks of colour, as the bars on pigeons wings.

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are often preserved in races of plants & animals, precisely in the same manner, as similar characters often pervade all the species of a genus or even family. Flowers in varying their colours, often become veined & spotted, & the leaves become divided, like true species: it is known that the varieties of the same flower plant never have red, blue & yellow flowers, though the hyacinth makes a very near approach to an exception, and different species of the same genus are have seldom, though sometimes have species flowers of these three colours. Dun-coloured horses having a dark stripe down their backs & certain domestic asses having transverse bars on their legs offer striking examples of a variation analagous to the to the characters of other species of the genus.) It

 

There is, however, as it appears to me a more important method of comparison between species & races, namely the character of the offspring when species are crossed & when races are crossed; & I believe, in no one respect, except sterility is there any difference. It would I think be a marvelous fact, if species are cre have been formed by distinct acts of creation that they should act upon each other in uniting, like races descended from a common stock. In the first place by repeated crossing one species, can like one race, absorb & wholly

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obliterate the characters of another species, or race of several species or races, as has been demonstrated by Koelreuter. Marvellous that one act of creation should absorb another or even several acts of creation. The offspring of same birth in of of species, or that is hybrids & the offspring of mong races or that is mongrels, resemble each other in being even those in at of the same litter of the same birth either intermediate as is most frequent in hybrids or in taking after resembling, sometimes closely one or the other parent; both sometimes retain a certain part or organ very like that of either parent; both as we have seen become in succeeding generations variable; a tendency to vary can be transmitted by both; in both for many generations there is a strong tendency to reversion to their ancestral forms. In the case of a hybrid Laburnum & of a supposed mongrel vine, different parts of the same plant take after their two parents. In the hybrids from some species & in the mongrels of some races, the offspring differ, according as which of the two species or of the two races, is the father ( as in the common mule & hinny) from the common horse & of & which the mother. Some races will breed together, which differ so greatly in size, that the dam often perishes in labor; so it is whith some species; when crossed. When a dam of one species has borne offspring to another, her succeeding offspring are sometimes stained (as in Ld. Moreton's mare by the Quagga, ( wonderful as the fact is) by this first cross; so

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agriculturists positively affirm is the case when one breed of pigs & sheep have produced one offspring by the sire of another breed.)

 

Let us sum up the second Chapter. If slight variations do occur in organic beings in a state of nature; if changes of condition from geological causes do produce any in the course of ages effects, analagous to those of domestication, on any, however few, organisms; &

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Let us sum up this Second Part Chapter of my work. If slight variations in instincts & structure & instincts do occasionally occur; If changes of conditions do produce effects like domestication under the necessarily varying conditions of nature, in some (very (exceedingly few at any one period of the earth's history) wild animals & plants;—

; and how can we doubt it, from what is actually known, & from what may be presumed, since thousands of organisms taken by man for sundry uses & placed in new conditions do vary have varied. If such variations tend to be heredetary, & how can we doubt it, when we see shades of feeli expression, peculiar manners, monstrosities of the strangest kind, diseases, even mortal [illeg] & a multitude of dif other peculiarities which characterize & form the endless races (there are 1200 kinds of cabbages) of our domestic plants & animals. (there are 1200 cabbages which can be raised from seed) and animals. If we admit that every organism maintains its place by an almost periodically recurrent struggle; & how can we doubt it, when we know that all tend to increase in a geometrical ratio (as is instantly seen, when the conditions become for a time more favourable) whereas, on an average the amount of food must remain constant; then there will be a natural means of selection preserv tending to preserve those those individuals with any slight deviations of structure more favourable to the then existing conditions & tending to destroy any with an deviations of an opposite tendency. If this be so, & there be no law of

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agriculturists positively affirm is the case when one breed of pigs & sheep have produced one offspring by the sire of another breed.)

 

Let us sum up the second Chapter. If slight variations do occur in organic beings in a state of nature; if changes of condition from geological causes do produce any in the course of ages effects, analagous to those of domestication, on any, however few, organisms; &

; and how can we doubt it, from what is actually known, & from what may be presumed, since thousands of organisms taken by man for sundry uses & placed in new conditions do vary have varied. If such variations tend to be heredetary, & how can we doubt it, when we see shades of feeli expression, peculiar manners, monstrosities of the strangest kind, diseases, even mental ones & a multitude of dif other peculiarities which characterize & form the endless races (there are 1200 kinds of cabbages) of our domestic plants & animals. (there are 1200 cabbages which can be raised from seed) and animals. If we admit that every organism maintains its place by an almost periodically recurrent struggle; & how can we doubt it, when we know that all tend to increase in a geometrical ratio (as is instantly seen, when the conditions become for a time more favourable) whereas, on an average the amount of food must remain constant; then there will be a natural means of selection preserv tending to preserve those those individuals with any slight deviations of structure more favourable to the then existing conditions & tending to destroy any with an deviations of an opposite tendency. If this be so, & there be no law of

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One of the commonest statements is plants (A) do not become acclimatised; & I have even observed that kinds not raised from seed, but propagated by cuttings &c, are instanced. A good instance has, however, been advanced in the case of Kidney Beans, which it is believed are now as tender, as when first introduced. Even if we overlook the frequent introduction of seed from warmer countries, let me observe that until an as long as the seeds are gathered promiscously from the bed, without & continual observation any and careful selection of which those plants, which have stood the climate best during their whole growth, this the experiment of acclimitisation has not been begun.

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nature, opposed to such limiting the possible amount of variation, new races of beings will,— perhaps only rarely & only in some few districts;— be formed.) ⁋ (That an opposed law of does a limit to variation does exist in nature, is assumed by most authors; though I am unable to discover a single fact on which this belief is grounded. (A) Are not all those tribes of plants & animals, of which we have the greatest number of races, the oldest domesticated? Considering the quite recent progress of systematic agriculture & horticulture is it not opposed to every fact, that we have exhausted the capacity of variation in our cattle & in our corn; even if we have done so in some trivial points, as their fatness or kind of wool?? Will any one say, that if horticulture continues to flourish, during the next 5000 years few centuries, that we shall not have numerous new kinds of the Potato & Dahlia? But take two varieties of each of these plants, & adapt them to certain fixed conditions & prevent any cross for 5000 years, & then bring again vary their conditions;— try every many a number climates & situations; & who will predict the number & degrees of differences, which might arise from two such these stocks. I repeat that we do know nothing of any limit of to the possible amount of variation, & therefore to the number & differences of the races, which might be produced by the natural means of selection, so infinitely more efficient, than those possessed by the agency of Man. Races thus produced, would probably be very "true"; & if from having been adapted to different

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conditions of existence they possessed different constitutions, they their offspring would probably produce perhaps or even probably be infertile. Such races would be indistin=guishable from species. But is there any evidence that the species, which surround us on all sides, have been thus produced? This is a question, wh independent of which an examination of the kingdom œconomy of nature, we might expect, would answer either in the affirmative or negative.—)

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Chapter III

 

On the variation of Instincts & other mental attributes; on the difficulties in this subject; and on analogous difficulties in respect with respect to corporeal structures.

 

I have as yet only alluded to the mental qualities, which differ greatly in different species. Let me here premise that,, as will be seen in the Second Part, as there is no evidence & consequently no attempt to show that all existing organisms have descended from any common parent-stock, but only those, which in the language of Naturalists, are clearly related to each other. Hence the facts & reasoning advanced in this chapter do not apply to the first origin of the senses, or of the chief mental attributes, such as of memory, attention, reasoning &c &c, by which most or all of the great related groups are characterized, anymore than they do apply to the first origin of life, or growth, or the powers of reproduction. The application of such facts, as I have collected, apply is merely to the differences of the primary mental qualities & of the instincts in each the species of the several great groups.)

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(26), In domestic animals every observer has remarked in how great a degree  in the individuals of the same species the dispositions, namely their courage, or timidity, pertinacity, suspicion, restlessness, or confidence, ill regard temper, pugnaciousness, affection, & care of their young, & sagacity &c &c vary. & (A) & From their dispositions being inherited, of which the testimony is unanimous, breeds & families & different breeds vary arise varying in these respects.— (A) I may instance the good & ill temper of Bees different stocks of Bees & of horses — the pugnacity & courage of fowls — the pertinacity & sagaci of certain dogs, as in bull-dogs, & the sagacity of others — for restlessness & suspicion, compare a wild rabbit reared with the greatest care from its earliest age, with the extreme tameness of the domestic breed of the same animal. The parents of (whether one or several) of the dog no doubt were wild & savage.— The offspring of the domestic dogs, which have run wild in Cuba, though caught quite young, are most difficult to tame, probably nearly as much so, as the original parents, from which the domestic dog descended.— The habitual periods of different breeds different families or stocks of animals differ, as the time of year of reproduction & the period of life when the capacity is acquired & times of roosting (in Malay fowls) & a tendency to roost in trees, though these are partly corporeal habits—, & may be compared to nearly similar habits in plants, which in a like manner vary.— Consensual movement, (as called by Müller) such are vary & are inherited, such as the cantering & ambling paces in horses — the tendency to point or the tumbling of pigeons, & their high flights & & perhaps the handwriting, which is sometimes so similar between father & sons, may be ranked in this class.

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(A)

It would require an a most able metaphysician to explain, in changes in how many primary qualities of the mind must be changed to these cause these diversities of complex dispositions. depend. —

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the Manners, & even tricks which perhaps are only peculiar manners, according to W. Hunter & my Father are distinctly inherited in cases where children have lost their parent in early infancy. The inheritance of expression, which often reveals the finest shades of character, is familiar to everyone. Again the tastes & pleasures of animals different breeds vary— thus the shepherd dog delights in chasing the sheep, but has no wish to kill them— the terrier (see Knight) delights in killing vermin & the spaniel & poin in finding game. But it is impossible to separate these mental peculiarities in the way I have done: the tumbling of pigeons is associated which I have instanced as a consensual movement might be called a trick & is associated with a taste for flying in a close flock at a great height— Certain breeds of fowls have a taste for roosting in trees. The different action of pointers & setters might have been adduced in the same class; as might the peculiar manner of hunting of the spaniel. In Even in the same breed of dogs, namely in fox-hounds, it is the fixed opinion of those best able to judge, that the different pups are born with different tendencies; some are best to find, their fox in the cover, some to are apt to run straggling, some are best to make casts & to recover the last scent &c & that these peculiarities undoubtedly are transmitted to their progeny.— Or again the tendency to point might be adduced, as a distinct habit, which has become inherited— as might the tendency of a true sheep-dog. (as I have been assured) very differently from any other dog attempted to run round the flock, instead of directly at them, as is the case with other young dogs when attempted to be taught. The transandantes sheep in Spain, which for some centuries have been yearly taken a journey of some several hundred

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miles from one province to another, know when the time comes & show the greatest restlessness, like migratory birds in confinement, & are prevented with the greatest difficulty from starting by themselves, which they sometimes do & find their own way— Young & old I believe There is a case on good evidence of a sheep, which when she lambed wd return across a mountainous country to her birt own birth-place, although at other times of year not of a rambling disposition: Her lambs inherited this same disposition & would go to lamb produce their young on the farm whence their parent came— & so troublesome was this habit, that the whole family breed was destroyed. These facts must lead to the conviction, however justly wonderful as it is, that the brain of an individual transmits a multitude of almost infinitely numerous shades of disposition, of tastes, of peculiar movements, & even of individual actions can be modified or acquired & transmitted by one individual & transmitted to its offspring. One if is forced to admit that mental relations phænomena, no doubt through their intimate connection with the brain, brain, can be inherited, like infinitely numerous & fine differences of corporeal structure. In the same manner as peculiarities of corporeal structure, slowly acquired or lost during mature life (especially cognisant in disease) as well as congenital peculiarities are inherited transmitted so it appears to be with the mind. The inherited inherited paces in the horse of horses tameness, good temper are have no doubt been acquired through compulsion during the life lives of the parents: seeing & temper & tameness may be modified in a breed by the treatment animals individuals they receive.

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Knowing that a pig has beeen taught to point one would suppose that this quality in pointers-dogs was pure was the simple result of habit, but some facts, with respect to the occasional appearance of a similar habit quality in other dogs, wd make one suspect that it originally appeared to in a less perfect degree, "by chance" that is from a congenital tendency in the parent of the parent breed breed of pointers. One cannot believe that the tumbling & high flight in a compact body of pige one breed of pigeons has been taught; & the case of the slight differences differences in kind in the manner of hunting tenpowers of in young fox-hounds, these can be no doubt they they are probably doubtless congenital. All the mental phænomena which are inheritable, whether actually pr produced in a slightly

The inheritance of the foregoing & similar mental phænomena is an ought ought to cre perhaps will to create somewhat less surprise, from the reflexion that in no case, do individual acts of reasoning, or movements or actions or other phænomena, connected with consciousness, & appear that highest attribute of the appear to be transmitted. An action, even a very complicated one, when from long practice it is performed unconsciously without any effort, & indeed in the case of many peculiarities of the mind manners, opposed to the will, is frequently by a common said according to a common expression to be performed "instinctively". Those cases of languages of songs, learnt in early childhood & absolutely quite forgotten, being suddenly recollected in perfectly repeated, during the illnesses unconscious sta unconsciousness of illness, appear to me only

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a few degrees less wonderful, than if they had been transmitted to a second generation.—

 

(27) Some of The chief characteristics of true true these instincts of wild animals seem appears to be their steadiness invariability & non-improvement during the mature life mature age of the individual animal;— the want absence of knowledge of the end, for which they perform the action is performed, being associated at the same time, however, in sometimes cases associated with a degree of reason; being subject to mistakes the instincts and being associated with certain states of the body or times of the year or day. In al most of these respects there is a a considerable pretty close resemblance in the above detailed cases of [illeg] acquired or modified instin mental phænomena, qualities which are inherited. No doubt the instincts of wild animals are more sturdy & uniform that those habits or qualities modified or recently acquired under domestication, in the same manner & from the same causes that the corporeal structure structure variations under this is less uniform, We have [illeg] The tumbling & other peculiarities of the tumbling pigeon in than in beings in their natural conditions. I have seen a young pointer out point point as perfectly fixedly, the first day it was taken out, as any old dog; Magendie says this was the case with a Retriever, which he himself reared: the tumbling of pigeons is not probably improved by age— : we have seen that in the case above detailed given, that the young sheep inherited the migratory instinct tendency to their particular birth place, the first time they lambed. (A) Ordinarily the acquired instincts of domestic animals seem to require a certain degree of education as generally in pointers & sheep-dogs retrievers to be perfectly developed: perhaps this holds good amongst wild animals in a wild state in a many in rather

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This last fact offers an instance of an inherited habit, or a domestic instinct being associated with a state of body; as do the transandantes sheep with a time of year.

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It seems pretty clear that Bees transmit knowledge from generation to generation.

 

(B)

& if man had never existed, he would never have ambled. The young pointer, pointing at white-stones appears to be as much a mistake of its acquired instinct, as in the case of flesh-flies laying their eggs on certain flowers instead of putrefying meat.

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greater degree, than wd at first be anticipated is generally supposed; for instance in the singing of birds & in the knowledge of proper herbs in the Ruminants. (A) Lord Brougham insists strongly, on ignorance of the end proposed being eminently characteristic of true instincts: this But this appears to me to apply to pointing many acquired heredetary habits; for instance in the case of the young pointer, alluded to before, which pointed perfectly so steadfastly the first day, that we were obliged several times to carry him away — not only pointed at sheep, at large white stones, & at every little bird, but likewise "backed" the other pointers: this young dog must have as ignor unconscious for what end he was pointing namely to facilitate his master killing game to eat, as is a butterfly who lays her eggs on a cabbage that caterpillars wd come from them & eat the leaves. So a horse that ambles instinctivly, manifestly is ignorant that he goes well inherits that peculiar pace for the ease of man; (B) However true the ignorance of the end may generally be, one sees that instincts are associated with some degree of reason;— for instance in the case of the Taylor-bird, which who spins threads with which to make its his nest, will use artificial threads when it he can procure them; so it is well recorded has been known that an a old pointer will has gone round has broken his point & gone round a hedge to drive out a bird towards his master.

 

(28)There is one other  method quite distinctive method by which the acquired instincts or habits acquired under

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domestication may be compared with those given by nature in by a test of a highly scrutinising which mus must, I think, of a fundamental kind,— I mean the comparison of the mental powers of mongrels and hybrids. Now the instincts, tastes, & dispositions of one breed of animals, when crossed with another, breed, for instance when a shepard dog with a harrier are are blended & appear in the same curiously mixed degree, both in the first & succeeding generations, exactly as happens with when one species is crossed with another. This would hardly be the case if there was any fundamental difference between the domestic & natural instincts; if the former was, to use a metaphorical expression, merely of a superficial.) quality,—

 

(29) With respect to the  variation of the mental powers of animals in a wild state, we know that there is a considerable difference in the disposition of the different individuals of the same species, as is recognized by all those, who have had the charge of animals in a managerie. — With respect to the wildness of animals, that is a particular fear of man directed particularly against man, which is appears to be as true as instinct, as the dread of a young mouse of a cat, we have excellent evidence, that it is slowly acquired & rendered becomes

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heredetary. by habit. It is also certain, that in a natural state, individuals of the same species lose or do not practice their migratory

instincts;—as woodcock in Madeira.— With respect to any variation in the more complicated instincts, it is is obviously most difficult to detect, even more so than in the case of corporeal structure, of which it has been admitted the variation is exceedingly small & perhaps scarcely any in the majority of species at any one period. — Yet, to take one excellent case of instincts, namely the nests of birds, those who have paid most attention to the subject, maintain that not only certain individuals seem to be able to build very imperfectly, but that a degree of variab difference in skill, may not unfrequently be detected between individuals. Certain birds, moreover, adapt their nests to circumstances; the water-ouzel makes no vault, when she builds under cover of a rock— the sparrow builds very differently when its nest is in a tree or in a hole, & the golden crested wren sometimes suspends its nest below & sometimes places it on the branches of trees. — As the instincts of a species are fully as important to its preservation & multiplication, as its corporeal structure, it is evident that if there be the slightest congenital differences, in the instincts & habits or if certain individuals during their life lives are

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induced or compelled to vary their habits, and if such differences are in the smallest degree more favourable under slightly modified external conditions to their preservation, such individuals must in the long run will have a better chance of being preserved & of multiplying. If this be admitted, a series of small changes, may, as in the case of corporeal structures, work great changes in the mental powers, habits, & instincts of any species.)

 

(30)Everyone  will at first be inclined to exclaim (as I did for a long time), that many of the more complicated & wonderful instincts could not be acquired in the manner here supposed. The third Second Part of this work is devoted to the general consideration of how far the facts general laws œconomy of Nature corroborate justifies or are opposes to the belief that related species & genera are descended from common stocks; but we may may here consider, whether the gradual acquirement instincts of animals offer such a primâ facie case of impossibility of gradual acquirement, as to justify the rejection of any such theory, however strongly it might be supported by other appearances facts.— I beg to repeat that I wish here to consider not the probability, but the possibility of complicated instincts have been acquired by the slow & long-

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This fossil is described by Mr O. as a mammiferous animal fully as large as the camel, referable to the order Pachydermata, but with affinities to Rum. & especially the Camilidæ

Perhaps the difficulty is in some small degree shown expressed by it the evident relationship of the fossil with the guanaco or llama, the present inhabitant of the most sterile districts. Mr O. describes the fossil, as belonging to the Pachydermata order, but with affinities to the Rum & especially. This affinty is chiefly shown by the — The animal must have been fully as large as the true camel— Mr Owen sums up his description by, remarking. [illeg] that  — It is well

 

This law has lately received the strongest confirmation with respect to Austra by the fossil collection of wonderful fossils, brought from there New South Wales by Sir T Mitchell & described by Mr Owen.— & with respect to S. America. by the discoveries of Lund.

 

A juster idea of the scale of the phænomenon, which took place during their [illeg] of Europe will perhaps be gained by supposing Eur

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continued selection of very slight (either congenital or produced by habit) modifications of foregoing simpler instincts, each modification being as useful & necessary to the species practising it, as the most complicated kind) ⁋.

(31) (First, to take the case of birds-nests; of existing species (almost infinitely few in comparison with the multitude which must have existed since the period of the New Red Sandstone of N. America, of whose habits we must always always remain ignorant) a tolerably perfect series could be made from eggs laid on the bare-ground, to others with a few sticks just laid round them, to a simple nest like the wood pigeon's, to others more & more complicated: now if, as some other state is asserted, there occasionally exists slight differences in the building powers of an individual, & if, which is at least probable, that such differences would be tend to be inherited, then we can see that it it is at least possible that the nidificatory instincts may have been acquired by the gradual selection during inf thousands & thousands of generations of the eggs & young of those individuals, whose whose nests were in some slight degree better adapted to the preservation of their young of their young, under the then existing conditions. of the parents. One of the most surprising instincts on record, is that of the Australian bush-turkey, whose eggs are hatched by the heat generated from the a huge pile of fermenting materials, which it congregates heaps together;; but here the habits of an allied species shows how this instinct might possibly have been acquired. This second

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inhabits a tropical district, where the heat of the sun is sufficient to hatch its eggs; but this bird buries its eggs, apparently for concealment under a lesser heap of rubbish, but of a dry nature, so as not to ferment. Now suppose this bird to migrate m range slowly into a cooler a climate; those which was cooler & where leaves were more abundant, now in that case, those individuals, which chanced to have their collecting instincts strongest developed, would make the largest a somewhat larger pile, & the eggs aided under the slightly cooler climate by the incipient heat of incipient fermentation would in the long run, wd be more freely hatched & would probably produce young ones, with the same collecting more highly developed collecting tendencies;— & of these again, those with the best developed powers would again tend to rear most young. Thus this strange instinct might possibly be acquired, the every individual bird being as ignorant of the laws of fermentation, & the consequent development of heat, as we know they must be.—)

 

(32) (Secondly to take the case of animals  shamming feigning, death (as it is commonly expressed) to escape danger. In the case of insects, a perfect series can be shown. from some insects, who momentarily stand still, to others who for a second slightly contract their legs, to others which will remain immovably drawn together for a quarter of an hour, & may be torn asunder or

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roasted at a slow fire, without sh evincing the smallest sign of sensation. No one will doubt that the degree & length, which of time during which each remains immoveable,, is well adapted to escape the dangers, to which it is most exposed; & few will deny the possibility of the change from one degree to another by the means & at the rate already explained. Thinking it, however, wonderful, that (though not impossible) that the attitude of death shd have been acquired by methods which imply no direct imitation of that individuals in that state, I compared nu several species, when feigning, as is said, death, with others of the same species, really dead, & their attitudes were in no one case really the same.)

 

(33)  ( Thirdly: In considering many instincts it appears to me quite necessary is useful to endeavour to separate the faculty by which they perform it & the mental power which urges to the performance, which can alone be truly is more properly called the are instinct. We have an instinct to eat eat, we have jaws so to give us the faculty to do so.— Bats a Their faculties are often unknown to us: bats, with their eyes destroyed, can av avoid strings suspended across the a room, we know not at present by what faculty they do this.— (Thirdly) Thus, also, in with migratory birds, they have a fa it is a wonderful instinct, which urges them at

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certain times of the year to direct their course in certain directions, but it is a faculty by which they know the time & find their way. With respect to time; Man, without seeing the sun, can judge to a certain extent of the hour, as can domestic animals must those anim cattle, in which come down from the inland mountains to feed on sea-weed left bare by the tides, although at a low constantly changing. at the changing hour of low-water. A hawk (D'Orbigny) seems certainly to have acquired a knowledge of a period of every 21 days.— in the cases, already given, of the sheep, the which travelled to their birth-place, to cast their lambs, & the sheep in Spain, which know their period time of march, we must suppose may conjecture that the tendency to m[illeg] move is associated, we may then call it instinctively, with some corporeal sensations.— With respect to the a tendency to travel in certain direction, of the migration we can easily conceive, how they its a tendency to travel in a certain course may possibly have been acquired, it, although we must remain ignorant how they follow birds are able to pursue preserve any direction whatever in a dark night over the wide ocean. I may observe that the power of some [illeg] savage races of mankind to find their way, although perhaps wholly different from the faculty of birds, is nearly as unintelligible to us: Bellinghausen, a skilful navigator describes with the utmost wonder, the manner in which some Esquimaux guided him to a certain point, by a course never straight through hum newly formed hummocks of ice, on a thick foggy day, when he with a compass, found it impossible

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from having no land-marks & from their course being so extremely crooked, could preserve no sort of uniform direction. (So it is with Australian savages in thick forests).— In North & south America, many birds slowly migrate travel northward & southward, urged on by the food they find, as the seasons change,; now suppose let them continue to do this, till, as in the case of the sheep in Spain, it has become an urgent instinctive desire, & they will gradually accelerate their journey,, according to their speed. They would cross narrow rivers, but & if these were converted by subsidence into narrow estuaries, & gradually ce during centuries into arms of the sea, still we may suppose their restless desire of hurtling onwards would impel them to cross such an arm, even if it had become of great width beyond their span of vision.— How they are able to preserve a course in any one direction, I have said, is a faculty unknown to us. To give another illustration of the means, by which I conceive it possible that the direction of migration may have been determined; Elk & rein deer in N. America, annually cross as if they could marvellously smell or see at the distance of m a hundred miles across wide tract of absolute desert to arrive at certain islands where there is a though (scanty) supply of food ,— the continual recent changes of temperature, which geology proclaims, renders it not impossible, that this desert tract

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formerly supported & guided led on those quadrupeds until lately formerly supported some vegetation, & thus these quadrupeds might have anually led on till they reached the more fertile spots & so acquired like the sheep of Spain, their migratory powers.) ⁋ to these now isolated spots, that the habit was thus naturally acquired, which now seems so marvellous.

 

(34) (Fourthly ; with respect to the combs of the Hive-Bee; here again we must look to some faculty or instinct means by which they make their hexagonal cells, without indeed we view these insects as mere machines. At present such a faculty is quite unknown; Mr Waterhouse supposes that several bees are led by their instincts to excavate a mass of wax to a certain thinness, & that the result of this, is that hexagons necessarily remain. Whether this or some other theory be true, some such means they must possess. They abound, however, with true inst instincts, which probably are the most wonderful, that are known. If we examine the little that is known, concerning the habits of other species of Bees, we find much simpler instincts; the humble bee, merely fills rude rude cells balls of wax with honey, & aggregates them together with little order in a rough nest of grass. If we knew the instincts of all the Bees, which ever have existed; it is not improbable in any high degree, that we should have instincts of every degree of complexity from actions as simple as a bird making a nest & rearing her young to the wonderful architecture & government of the Hive-bee;— at least such is possible

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, which is all that I am here considering.) & I need not repeat that if

 

(35). Fifthly Finally;.— I will briefly consider under the same point of view one other class of instincts, which have often been advanced as truly wonderful, namely parents bringing food to their young, which they themselves neither like or partake of;— for instance the common sparrow, a granivorous granivorous bird, feeding its young on with caterpillars. We might, of course, look into the case still earlier & seek search search how are instincts of feeding in the parent of feeding its young at all, was first derived; but it is useless to waste time in conjectures on a series of gradations from the young feeding itself themselves & being slightly & occasionally assisted in its in their search, to its their entire food being brought them—. With respect to the parent bringing a different kind of food we m from its own kind, we may suppose either that the remote stock, whence the sparrow & other congenerous birds have descended, was insectivorous, & that its own habits & structure have been changed, whilst its ancient instincts with respect to its young have remained unchanged;— or we may suppose that the parents have been induced induced compelled to vary slightly the food of their young, either by a slight scarcity of the proper kind (or by the instincts of some individuals not being so truly developed,) & that in this case, those young which were most capable of surviving, were necessarily most often preserved & would themselves be in time converted into become parents, having [words illeg] slightly ne similar tendencies & would be being similarly compelled to alter the food for their young. on having

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slightly aberrant tendencies with their parents In the case of insects those young those animals, the young of which feed themselves, in changes in their instincts for food & in their structure, might be selected from slight variations, just as in mature animals.— Again when the food of the young depends on where the mother places her eggs, (as in the case of the caterpillars of the cabbage butter-fly), we may suppose that anciently the she placed her for eggs in less restricted stations the ancient the parent stock of this species, deposited her eggs, on several kinds sometimes on one kind & sometimes on another of congenerous of plants ( as some species now do) & that if the cabbage suited the caterpillars better than any other of plant, tha such the caterpillars wd be most plentifully reared of those butterflies, which had chosen the cabbage, would be most plentifully reared & would produce butterflies, more apt to lay their eggs on the cabbage, then on the other congenerous kinds.)

 

(36) Finally, however However vague & unphilosophical are these conjectures, may appear, they serve. I think, to show that one's first impulse utterly to reject any theory whatever, implying a gradual acquirement of those instincts, which for ages have excited man's solemn admiration, ought to may at least be certainly checked delayed. Once grant, that tastes

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dispositions, tastes, actions, or habits can be slightly modified either by the an slight congenital differences, (we must suppose in the brain) or by the force of external [illeg] circumstances & that such slight modifications can be rendered inheritable—

— a proposition which no one can deny— amongst one reject,— & it will be impossible difficult to put any limit to the complexity & wonder of the tastes & habits, which may possibly be thus acquired.

 

(37)He will (After the past discussion it will perhaps be convenient here to consider whether any particular  corporeal organs, or the entire structure of any animal are so wonderful as to justify the rejection primâ facie of our theory. In the case of the human eye, as with the more complicated instincts, no doubt one's first impulse to is to peremptori to entirely reject every such theory. The habit of viewing the perfect & wonderful adaptation of single organs, without at the same time.

utterly reject every such theory. Nevertheless the same remarks, with which the last made at the close of the last paragraph, are here equally applicable, that is namely that no organs, But if the eye from its most complicated forms can be shown to graduate into an exceedingly simple state, it is clear (for in this work we have

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nothing to do with the first origin of organs in their simplest forms) that it may possibly have been acquired in the manner supposed by general selection of slight, but in each case useful deviations. Every naturalist, when he meets with any new & singular organ always expects to find & looks for, other & simpler modifications of it in other beings.— In the case of the eye we can have a multitude of different forms, more or less simple, not graduating into each other, but separated by sudden gaps or intervals; but we must recollect how incomparably greater would the multitude of visual structures be, if we had the eyes of every fossil, which has ever existed. On the immen We shall discuss the probable immense vast proportion of the extinct to the recent in the succeeding Part.— Notwithstanding the large series Nevertheless of existing eyes forms, it is most difficult to ever to conjecture by what intermediate forms stages, the m very many complicated simple organs could possibly have have graduated into simple complex ones: two considerations but it should be here borne in mind,— first that a part having originally a wholly different function may on the theory of gradual selection be slowly worked into quite another use; it is only thus it has lately that it has been shown that the swimming bladder of fishes is a metamorphosed part of the ear— and the swimming bladder itself is again often metamorphosed into lungs; the jaws, again, of insects are metamorphosed legs, & in this latter case we can trace the steps of the so-called metamorphosis: as metaphor only serves as illustration not as a proof Secondly that as considerable modifications of structure may accidentally arise from the simple laws action of reproductive systems, in certain individuals of a species, without any relation to the habit of the animals, = without any long selection = but which if

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useful to it would cause such individuals to be selected & to be multiplyed; thus the ruff of certain pigeons, the additional toe of the Dorking fowl. the horn on the head of another variety— — the hooked end of the calyx of the cultivated teazle— have evidently been produced "accidentally" as far as the habits of the organisms are concerned, but they might possibly come to be worked into some good of the individual, instead of for the good or amusement of man.— In considering the steps In endeavoring to conjecturing by what steps stages any complicated organ in an individual species may have arrived at its present stage state, although we may look to other the analagous analagous organs in other existing organisms species; we can should do this merely to aid & guide our imaginations; for we to know the real steps stages, we must look only through one line of species to an one to the successive ancient stock, whence through a long line of species succession, from from which the individual, species has descended whose particular organ we are looking at has descended. In considering the eye of man for instance, though we may look at the eye of a Fish or of molluscous animal or of an insect, as some guide, it is improbable in the in a high degree, a proof how simple an organ will serve the some of the ends of vision; & at the eyes of a fish or reptile we must remember that any existing animals organisms should have the same organs as others, which lived in the remotest geological periods. it is a mere chance if any existing and at the eye of a fish, as some a nearer guide of the kind manner of simplification, we must remember that it is a mere chance if any existing organic being has preserved any one organ in exactly the

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quite another use: the gradations of forms, from which naturalists believe in the hypothetical metamorphosis of part of the ear into the swimming bladder in fishes, & in insects of legs into jaws, shows how the manner in which this is possible. As under domestication, modifications of structure take place, without continued selection which man finds very useful, without long or [illeg] valuable for curiosity, as the hooked calyx of the teazle, or the ruff round some pigeons necks; so it some in a state of nature, some small modifications, apparently beautifully adapted to certain ends, may perhaps be produced in a state of nature from the accidents of the reproductive system, & be at once propagated by natural without long-continued selection for the such ends. In

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quite another use: the gradations of forms, from which naturalists believe in the hypothetical metamorphosis of part of the ear into the swimming bladder in fishes, & in insects of legs into jaws, shows how the manner in which this is possible. As under domestication, modifications of structure take place, without continued selection which man finds very useful, without long or [illeg] valuable for curiosity, as the hooked calyx of the teazle, or the ruff round some pigeons necks; so it some in a state of nature, some small modifications, apparently beautifully adapted to certain ends, may perhaps be produced in a state of nature from the accidents of the reproductive system, & be at once propagated by natural without long-continued selection for the such ends. In

[85v]

the steps In endeavoring t conjecturing by what steps stages any complicated organ in an individual species may have arrived at its present stage state, although we may look to other the analagous analagous organs in other existing organisms species; we can should do this merely to aid & guide our imaginations; for we to know the real steps stages, we must look only through one line of species to an one to the successive ancient stock, whence through a long line of species succession, from from which the individual, species has descended whose particular organ we are looking at has descended. In considering the eye of man for instance, though we may look at the eye of a Fish or of molluscous animal or of an insect, as some guide, it is improbable in the in a high degree, a proof how simple an organ will serve the some of the ends of vision; & at the eyes of a fish or reptile we must remember that any existing animals organisms should have the same organs as others, which lived in the remotest geological periods. it is a mere chance if any existing and at the eye of a fish, as some a nearer guide of the kind manner of simplification, we must remember that it is a mere chance if any existing organic being has preserved any one organ in exactly the

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same condition, as it existed in its past stocks the ancient species at the remote geological periods.)

(38)  (A) (A) (A) (If instead of looking as above at any one certain individual organs we look in order to speculate on the steps stages by which their parts have been matured & selected, we consider an individual animal, we meet with the same or greater difficulty, but which, I believe, as in the case of single organs, rests entirely on our ignorance. It may be asked by what intermediate forms could, for instance, a Bat possibly have passed;— but the same question might have been asked with respect to the Seal, if we had not been familiar with the other otter & other semi-aquatic animals. carnivorous quadrupeds. But in the case of the Bat, who can say what might have been the habits of some parent-form with less developed wings, when we know now have a structure insectivorous opossums & herbivorous squirrels fitted for merely gliding throught the air. like the flying squirrels or opossums. One species of bat is at present partly aquatic in its habits! Woodpeckers & tree-frogs are especially adapted, as their names express, for climbing trees; yet we have species of both creatures these animal inhabiting the open plains of La Plata, where a tree does not exist; I might

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(The state of certain structures is thought by some naturalists to be of no use to the possessor, but to have been formed wholly for the good of other organisms; thus certain fruit & seeds have been thought to have been made nutritious for certain animals,— numbers of insects especially in their larval state, to exist for the same end,— certain fish to be bright-coloured to aid certain birds of prey in catching them &c. Now could this be proved (which I am far from admitting) the theory of natural selection would be quite overthrown; for it is evident that selection depending on the advantage of one individual with some slight deviation over others, could not result would never produce a structure or quality profitable only to another species. No doubt one being takes advantage of qualities in another, & may even cause its destruction extermination, but this is far from proving that this quality was produced for such an end. It may be advantageous to a fis plant to have its seeds attractive to animals, if one out of a hundred or thousand escapes being digested & thus offers a better means of aids its dissemination: the bright colours of a fish may be of some advantage to it, or more probably may result from exposure to certain conditions in favourable haunts for food, notwithstanding it becomes subject to be preyed caught more easily by certain birds.)

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argue for this circumstance that the a structure eminently fitted for climbing, was derived descended from forms inhabiting a country when a tree did not exist. With Notwithstanding these & a multitude of other well-known facts, it has been maintained by several authors, that, one species with h, for instance of the carnivorous carnivorous order could not pass into another, for instance into an otter otter because in its transitional state its habits would not be adapted to any any proper conditions of life;— but the jaguar for is a thoroughly terrestrial quadruped in its structure, yet it takes freely to the water & catches many fish;— will it be said that it is impossible, that the conditions of its country might become such that the jaguars were should be driven to feed more on fish, than they now do; & in that case is it impossible,— is it not probable,— that every any the slightest deviation in its instincts, its form of body,— in the width of its feet & in the extension of the skin (which already unites the base of its toes) would give such individuals a better chance of surviving & propagating young with similar mos slight, barely perceptible though thoroughly exercised deviations? Who will say what th[illeg] could thus be effected in the course of five or ten or twenty thousand generations? — Who can answer the same question, with respect to instincts? If no one can, the possibility (for we are not here considering the probability) of complicated simple organs or organic beings being modifyed by natural selection & the effects of external agencies into complicated ones, ought not to be absolutely rejected.)

Who can answer the same question, with respect to instincts? they cannot, the possibility (which is all we are here considering) cannot ought not to be disputed —

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Part II.

On the evidence, on favourable & opposed to the view, that species are naturally-formed races, descended from common stocks.

 

Chapter I

On the number of intermediate forms, required on the theory of common descent; & on their absence in a fossil state.

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Part III

Reasons for & against believing that species have been formed produced, in the manner explained in the Second First Part

 

Chapter I

I may must here premise that according to the view ordinarily recieved, all the myriads of organisms, which have at any during past & present times peopled this world, have been created by so many distinct acts of Creation. It is impossible to reason concerning the will of the Creator, & therefore according to this view we can see no cause, why the or why not the individual organism should have been created on any fixed scheme. It would, however, be too improbable to suppose That all the organisms of this world have been created produced on a scheme, is certain from their resemblan affinities; general resemblance affinities; & if such resemblances could this scheme can be shown to be the same with that which would result from the allied organic beings having descending from common stocks, it would be becomes highly improbable that they had have been separately created by individual acts of the will of an Creator: which For As well might it be said, that although the planets move in courses conformally to the law of gravity, yet we ought to attribute the course of each planet to the word individual act of the will of the Creator. It is in every case more conformable with what we know of the government of this earth that the Creator shd only have given imposed only general laws. As

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Chapter — on the number of requisite intermediate forms required on the theory of com desct; & on their absence in a fossil state.

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Part II.

On the evidence, on favourable & opposed to the view, that species are naturally-formed races, descended from common stocks.

 

Chapter I

On the number of intermediate forms, required on the theory of common descent; & on their absence in a fossil state.

I may must here premise that according to the view ordinarily recieved, all the myriads of organisms, which have at any during past & present times peopled this world, have been created by so many distinct acts of Creation. It is impossible to reason concerning the will of the Creator, & therefore according to this view we can see no cause, why the or why not the individual organism should have been created on any fixed scheme. It would, however, be too improbable to suppose That all the organisms of this world have been created produced on a scheme, is certain from their resemblan affinities; general resemblance affinities; & if such resemblances could this scheme can be shown to be the same with that which would result from the allied organic beings having descending from common stocks, it would be becomes highly improbable that they had have been separately created by individual acts of the will of an Creator: which For As well might it be said, that although the planets move in courses conformally to the law of gravity, yet we ought to attribute the course of each planet to the word individual act of the will of the Creator. It is in every case more conformable with what we know of the government of this earth that the Creator shd only have given imposed only general laws. As

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Whilst As long as no method was known by which species races could become exqusitely adapted, in the exquisite manner by exquisite means to various ends,— whilst the existence of species was thought to be proved by the sterility of their offspring, when crossed, it was allowable to attribute each organism to an individual act of Creation. But in the two former Parts, it has, I think, been shown that the production under the existing condition of things of exquisitely adapted species is at least possible. or even probable, under What Is there then any direct is the evidence, of in favour or against this view: I believe that the geographical distribution of organic being in past & present times; the kind of affinity link linking them together — both; their so called 'metamorphs' structure and & 'abortive' organs, are in fav appear in favour of this view. On the other hand, the want of want of imperfect imperfect evidence of the continuousness of the organic series, is against this though as far as the evidence goes it is favourable, which, as we shall immediately see, is required on our theory, is against it & is the most weighty objection. The evidence, however, even on this point as far as it goes, is favourable; and considering the imperfection of our knowledge, especially with respect to past ages, it wd have been strange be surprising, if the evidence drawn from such sources had were not also been imperfect.)

(As I suppose that species have been formed in an analogous manner with the varieties of the domesticated animals & plants, so must there have existed intermediate forms between all the species of the same group, not differing more than recognized varieties differ.—

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It must not be supposed necessary, that there should have existed forms, exactly intermediate in character between any two species of a genus, or even between any two varieties of a species; but it is necessary that there should have existed every intermediate form between the one species or variety & the common parent-form and likewise between the second species or variety, & this same common parent. Thus it does not necessarily follow that there even has existed a series of intermediate (as sub-varieties forms (differing no more than the ocasional seedling sports from the same seed-capsule between a Broccoli & common Red Cabbage, but it is necessary certain, that there have existed between Broccoli & the wild parent cabbage a series of such intermediate seedlings & again between Red Cabbage & the wild parent cabbage: so that the Broccoli & Red Cabbage are linked together, but not necessarily by directly intermediate forms. It is of course possible they may have have been been directly intermediate forms, for the Broccoli may have been a descen long since descended from a common Red Cabbage & this from the wild cabbage.— So, on my theory, it must have been with species of the same genus.— Still more must the supposition be avoided, that there has necessarily ever existed directly intermediate forms between any two genera or families;— thus for instance between the genus Sus & Rhinoceros Tapir, although it is necessary that such intermediate forms (not differing more than the varieties of our domestic animals) should have existed between the genera Sus & Rhinoceros Tapir some unknown parent form, & Tapir with this

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same parent form. which parent The latter may have differed (& where families or orders are in question probably have differed) more from Sus & Tapir, than these two genera now differ from each other. Hence In this sense, according to our theory, there has been a gradual passage (the steps not being wider apart, than our domestic varieties) between the species of the same genus, between genera of the same family, & between families of the same order, & so on as far as facts, hearafter to be given, lead us; and the number of forms which must have at former periods existed, thus to make good this passage between different species, genera & families, must have been astonishingly almost infinitely great,.

What evidence is there is there of a number of intermediate forms having existed, making a passage in the above sense does there exist. between the species of the same groups? Some naturalists have supposed that if every fossil, which now lies entombed, together with all existing species were collected together, a perfect linear series in every great class would be formed. Considering the enormous number of species requisite to effect this, especially in the above sense of the forms not being directly intermediate between the know existing species & genera, but only intermediate by being linked linked through a common, but often widely different, ancestor, I think this supposition highly improbable.— I do am however far from

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underrating the probable number of preserved fossilized species: no one who attends to the wonderful progress of palæontology during the last few years, will doubt that we as yet have found, only an very exceedingly small fraction, of the species buried in the crust of the earth. Although the almost infinitely numerous intermediate forms in any no one class may not have been preserved, it does not follow that they have not existed. As for The fossils, which have been discovered, it is important to remark, do tend as far as, the little way they go, to make good the series; for as they observed by Buckland they all fall into or between existing groups. Moreover, those that fall between our existing classes groups, fall in, according to the manner required by our theory; for they do not directly connect an two existing species of different groups, but they connect the groups themselves: thus the Pachydermata & Ruminantia are now separated by several characters amongst which may enumerate, the Pachydermata have both a tibia & fibula, whilst the Ruminantia have only a tibia; now the fossil Macrauchenia has a leg bone (as we exactly intermediate & likewise has some other intermediate characters. But the Macrauchenia does not connect any one species of Pachydermata with some one other of Ruminantia, but it shows that there have existed forms & groups intermediate between

two groups have at one time, by the existence of other been less widely divided.

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So have fish & reptiles been at one time less widely divided Generally than they now are. These & such like are all steps, though few & far between, [illeg] in a series of the kind required by my theory. Generally the more ancient the fossil, the more often it falls between existing groups, or into small existing groups which now lie between other large existing groups.— Cases like the foregoing, of which there are many, form steps, though few & far between, in a series of the kind required by my theory.)

As I have admitted the high improbability, that if every fossil were disinterred, they would compose it is highly improbable that a nearly perfect series of the kind required in each of the great Divisions of nature, could would of the kind required: consequently I freely admit, that if those geologists are in the right, who consider existing several lowest-known formation as containing anything like a near approach a records,, at all perfect, of commencing when living beings first appeared on this world, contemporaneous with the first appearance of life, or the several formations as at all closely consecutive or any one formation as containing a nearly perfect record of any one of kingdoms groups of the organisms of any one group then & there existing which existed during the whole period of its deposition in that part, quarter existed of the globe— if such propositions are to be accepted, my theory must be abandoned.)

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(If the Palæozoic system is really contemporaneous with the first appearance of life, my theory must be abandoned, both in as much as it limits from shortness of time the total number of forms which can have existed on this world, & because the organisms, as Fish, shells Mollusca & Star-fish, found in its lower beds cannot be considered, as the parent-form of all the successive species in these classes. But no one has yet overturned the arguments of Hutton & Lyell, that the lowest formations containing organic remains known to us, are only those which have escaped being metamorphosed: if we argued from some considerable districts, we might have supposed that even the cretaceous system was that in which life first appeared. From the number of distant points, however, in which the Silurian system has been found to be the lowest & not always metamorphosed, there are some difficulty objections to Hutton's & Lyells's view; but we must not forget, that the now existing land, forms only ⅕ part of the superficies of the globe, & that this fraction is only imperfectly known.— With respect to the fewness of the organisms, preserved in the Silurian & other Palæozoic formations, there is less difficulty, in as much as (besides their gradual obliteration) we might can expect only those formations of this vast antiquity to escape entire denudation, only when they have been accumulated over a wide area & have been subsequently protected by vast superimposed

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deposits: now this would could generally only be affected hold good with deposits, accumulating in a wide & deep ocean, & therefore unfavourable to the presence of many living things. A mere local, narrow, & not very thick strip of matter, deposited along a coast, where organisms must abound, would have no chance of being preserved to the present time from such immensely distant ages.)

 

(If the several known formations are at all nearly consecutive in time & preserve a fair record of the organisms which have existed, my theory must be abandoned. But when we g[illeg] consider the great change in mineralogical nature & texture between successive formations, what vast & entire changes in the geography of the surrounding countries must have been effected, thus wholly to have changed the nature of the deposits on the same area. . What time such changes must have required! Moreover how [illeg] often has it not been found, that betweeen two conformable & apparently immediately successive deposits, is another adjoining district, a vast pile of water-worn matter is interpolated in an adjoining districts. We have no means of conjecturing in many cases how long a period has elapsed between successive formations, for the species are often wholly different: as remarked by Lyell in many some cases probably as long a period has elapsed, between two formations as the whole Tertiary system, itself broken by wide gaps.

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Consult the writings of anyone who has particularly attended to any one stage in the Tertiary system (& indeed of every system) & see how deeply impressed he is with the time required for its accumulation. Reflect on the years elapsed in many cases since the last latest beds containing only living species have been formed;— see what Jordan Smith says of the 20,000 years since the last bed, which is above the boulder formation of in Scotland, has been upraised; Reflect or of the far longer period since the recent beds of Sweden have been upraised 400 feet, & then what an enormous period the Boulder formation must have required, & yet how insignificant are the records (although there has been plenty of elevation to bring up submarine deposits) of the shells, which we know then existed at that time.— reflect on the number of organisms which think over Think then over the entire length of the Tertiary epoch, & think over the probable length of the intervals, separating the Secondary deposits. Of these deposits, moreover, those consisting of sand & pebbles have seldom been favourable, either to the embedment or to the preservation of fossils.)

 

Nor can it be admitted as probable that any one Secondary formation contains a fair record even of those organisms remains of the same quarter of the world which are most easily preserved, namely hard maMrine bodies. (A) With a few local exceptions Some of the secondary formations which contain most marine remains, appear to have been formed in a wide & not deep sea, & therefore only those comparatively few marine animals which live in such situations would be preserved. In all cases On indented rocky coasts,, or any other coast, where sediment is not accumulating,

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(A.) in text.In how many cases have we not certain evidence that between apparently closely consecutive beds,  the lower one existed for an unknown time as land, & was covered with trees., or was marked by footsteps

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although often highly favourable to marine animals, none can be preserved embedded: where pure sand & pebbles are accumulating few or none will be preserved. I may with form here refer to instance the great western line of the S. American coast, tenanted by many peculiar animals, of which none will probably will be preserved to a distant epoch. From these causes & especially from small local deposits, formed near along a line of coast steep above & below water, being of little breadth,, being less favourable likely & therefore more likely to be subsequently denuded & worn away, to be subsequently protected from denudation by [illeg] thickly superimposed masses, we can see must admit, we can see why the texture & nature of those secondary formations it is improbable that our secondary deposits should seldom cont should not probably contain a fair record of the Marine Fauna of any one period. The East Indian archipelago offers an area, as large as most of our secondary deposits, in which there are wide & shallow seas, teeming with Marine animals & in which sediment is accumulating; now supposing that all the hard marine animals, were preserved to a future age, excepting those which lived on rocky shores were where no sediment or only sand & gravel were accumulating, & excepting those preserved embedded in narrow in the deeper parts, of the sea along the coasts steeper coasts, where only a narrow fringe of sediment was accumulating, supposing all this, how poor a notion should [illeg] would a person at this distant future age, have of the Marine Fauna of the present day. Lyell has compared compared the geological series to a work of which only the few latter but not consecutive chapters have been preserved, & out of which

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, it may be added, very many leaves have been torn, the remaining ones only illustrating a scanty portion of the Fauna of each period. On this view, the discoveries records of anteceding ages confirm my theory; on any other they destroy it.)—

 

(Finally if we narrow the question into; why we do not find every interm in some instances every intermediate form between any two species; the answer may well be, that the average duration of each specific form (as we have good reason to believe) is immense in years, & that the transition could only according to my theory be effected by numberless small gradations; & therefore that we should require for this end a most perfect record, which the foregoing reasoning teaches us not to expect. It might be thought that in the sa a vertical section of great thickness in the same formation some of the species might ought to be found to vary in the upper & lower parts, but it may be doubted whether any formation has gone on acccumulating without any break for the a period as long as the duration of a species; & if it had done so, & if it had done so, we should require a series of specimens, from every part. How rare must be the chance of sediment accumulating for some 20 or 30, thousand years on the same spot, with the bottom subsiding, so that a proper depth might be preserved

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for the any one species to continue living: what an amount of subsidence wd. be thus required, & likewise this subsidence must not destroy the source, whence the sediment continued to be derived.— In the case of terrestrial animals, what chance is there, when the present time is become a pleistocene formation (or later at an (earlier or later period than this, sufficient elevation to expose submarine beds could not be expected), that a what chance is there that future geologists will make out the innumerable transitional sub-varieties through which the short-horned & long-horned cattle (so different in form shape) have been derived from one & the same parent stock: yet this transition has been affected in the same country, & at in a far shorter time, than would be probable in a wild state,— both contingencies highly favourable to for the future hypothetical geologist, being enabled to trace the variation.))

 

Chapter II

Gradual appearance & disappearance of Species.

 

In the Tertiary system, in the last uplifted beds we find all recent the species recent & living in the immediate vicinity; in rather older beds we find its only recent species, but some not living in the immediate vicinity; we then find beds with two or three or a few more extinct Species; or with more we then find gaps in the percentage, but yet, with many living species considerably more extinct species, but with gaps in the regular increase; & finally either we have beds with only two or three or perhaps not one living species. Most geologists believe

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that the gaps in the percentage, that is the sudden increments in the number of the extinct in the stages of the Tertiary system are due to the imperfection of the geological record. & not really to Hence we are led to believe that the species in the Tertiary system have been gradually introduced; & from Analogy to carry on the same view to the Secondary formations. In these latter, however, the entire whole groups of species generally come in abruptly; but this would naturally result, if, as argued in the foregoing section, chapter, these Secondary deposits are separated by wide epochs. Moreover it is important to observe, that with our increase of knowledge, the gaps between the Secondary older formations become fewer & smaller; how beautifully has the Devonian system come in between the Carboniferous & Silurian formations. I need hardly observe, that by our theory, the slow & gradual appearance of new forms follows from our theory;— for to form a new species, an old one a species must not only become be plastic in its organization, becoming so probably from changes in the surrounding conditions of its existence; but must be these changes must make room a place in the natural œconomy of the district must be made for the selection of some new organization, modification of it' its structure, better fitted to the new surrounding conditions, than are any that of the of the surrounding species. surrounding individuals of the same species & probably other antagonist species than are the other that of the other other [illeg] individuals of the same or other species.) or of other corresponding species.)

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On the contrary, the law, which has been made out by independent observers, with reference to distinct epochs, namely that the wider the geographical range of a species is, the longer is its duration in time, seems entirely opposed to any g universal exterminations. The fact of species of mammiferous animals and Fish being renewed at a quicker rate than Mollusca; & of then the terrestrial genera being renewed quicker than the marine; & the marine mollusca being again renewed quicker than the Infusorial animalcules, all seem to show that the extinction & renewal of species does not depend on general catastrophes, but on the particular relations of the several classes to the condition to which they are exposed. Some authors seem to consider the fact of a few species having survived amidst a number of extinct forms (as is the case with a tortoise & crocodile out of the vast number of extinct sub-himalayan fossils) as strongly opposed to the view of species being mutable. No doubt this is would be the case, if it were presupposed with Lamarck, that there was some inherent tendency to change & development in all species; for which supposition I see no evidence. As we see some species at present adapted to a wide range of conditions, we so we might may suppose, that such species would survive unchanged & unexterminated for a long time; time being generally being from geological causes, a corelative of changing conditions. Why How at present one species becomes adapted to a wide range, & another species to a restricted range of conditions, I am quite unable in most cases to conjecture.).

is of difficult explanation.) ⁋

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Gradual Extinction of Species>

 

In the Tertiary system, the same reasoning facts, which makes us admit, that new species have slowly appeared, would lead us to believe admit to the admission, that they old ones have slowly disappeared; & by analogy may be carried on one is induced to extend this belief to the Secondary & Palæozoic epochs. In some cases, as the subsidence of a flat country, or the breaking or joining of an isthmus, & the sudden inroad of many new & destructiive species, extinction might be locally sudden. But The view, entertained by many geologists, that each Fauna of each Secondary epoch has been suddenly over destroyed over the whole world, so that no successors could be left for the production of new forms is subversive of my theory, but I see no grounds whatever to admit such a view. (A) (The extinction of a species, especially of the larger quadrupeds, of which we imagine we better know the conditions of existence, has been thought little less wonderful than the appearance of new ones species, & has led I think, chiefly led to the view belief of universal catastrophes. In such views, I formerly joined. the consideration of the numerous recent extinction of When considering the wonderful disappearance within a late period, whilst living recent shells were living, of the numerous great & small mammifers of S. America, one is strongly induced to join with the catastrophists. I believe, however, that very erroneous views are held on this subject.— As far as is historically known, the disappearance of species with from any one quarter of country or from the whole world, has been slow,— the species becoming rarer & rarer, locally extinct, & finally & at last being lost. It may be objected that this has been effected

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by man's direct (or indirect) agency, or by his indirect agency in altering the state of the country; in the latter case, however, it would be difficult to draw any just distinction between his agency & natural agencies. But we now know in the later Tertiary deposits, that shells, first become rarer & rarer in succeeding the successive beds & finally disappear: it has happened, also, that shells abundant in a fossil state, & long thought to be extinct have been found to be a rare species still living species, but very rare ones. If the rule is that organisms become extinct by becoming rarer & rarer, we ought not to view their extinction, even in the case of the larger quadrupeds, as anything wonderful & out of the common course of events. For no naturalist thinks it wonderful that one species of a genus being should be rare & another abundant, common wonderful, although he be although each of equal fertility; notwithstanding he be quite incapable of explaining the causes of the comparative rareness. Why is one species of Willow-wren or Hawk or woodpecker common in England & another extremely rare; why at one the Cape of Good-Hope is one species of Rhinoceros or antelope far more abundant than any other species? why in India is the black tiger rare & common tiger frequent? Why again is the same species much more abundant in one district of a country than in in another district? No doubt there are in each case good causes; but they are unknown & unperceived by us. May we not then safely infer, that these as certain causes which are acting unperceived around us, & are causing making one species to be common &

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I may give a single instance of a check causing local extermination which might long have escaped discovery; the horses though swarming in La Plata & under apparently the most unfavourable pl conditions in the scorched & alternatively flooded plains of Caraccas, will not in a wild state extend beyond a certain degree of latitude into the intermediate country of Paraguay; because this is owing to a certain fly depositing its eggs on the navels of the foals: man as, however, man with a little care care can rear horses abundantly in Paraguay, no doubt we must add to the problem fly occasional greater less destruction, during drought, & loss from the jaguars & other a the problem of its extinction is probably complicated by the greater exposure of the wild horses to occasional famine from the droughts, to the attacks of the jaguar, or being & other such evils. In the Falkland Islands, the check to the increase of the wild horse, seems to be the loss of the sucking foals, from the travelling across of the mares for food stallions compelling the mares to travel across bogs & rocks in search of food

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another exceedingly rare, that they might equally well cause their final extinction, without being perceived by us. We should always bear in mind, that there is [illeg] the a recurrent struggle for life in every organism & that in every country, (not undergoing changes in its physical conditions) a destroying agency is always counteracting the geometrical tendency to increase in every species; & yet without our being able to tell at with certainty at what period of their life or at what periods of the year, destruction falls heaviest. Ought we then to expect to trace the steps by which this destroying power, always at work & scarcely perceived by us, becomes increased; & yet if it be increased in the least degree continue to increase ever so slowly, without the fertility of the species in question be likewise increased, the average number of that individuals of that species must decrease become decrease & may will become finally lost (A) From our more intimate aquaintance with domestic animals, we cannot conceive their extinction without some glaring agency; we forget that in a state of Nature, where other animals were are ready to fill up their place, that they would undoubtedly in some part of their lives be acted on by a destroying agency keeping their number on an average constant. If Bos taurus our common cattle was known only in as Australia as a wild S. African species, we should feel little no surprise at learning that it was a very rare species; & this very rarity would be a stage towards its extinction. Even in man, so infinitely better known than any other inhabitant of this world, how impossible impossible it has been found, without statistical

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tables, calculations, to judge the proportion of births & deaths, of the duration of life, & of the increase & decrease of populations, ; & still less of the causes of such changes: & yet, [illeg] as so often has been reported, decrease in numbers or rarity seems to be the high-road to extinction. To marvel at the extermination of a species (A)

Geographical distribution in present

and past Times.

P[illeg]   if consider if [illeg]

Chapter III

 

In the following discussion, I shall chiefly refer to terrestrial Mammifers, in as much as they are better known; their differences in different countries, strongly marked; & especially as the necessary means of their transport are more evident, & confusion from the accidental removal conveyance by man under existing circumstances of a form from one district to another district is less likely to arise. It is known that all all Mammifers ( & as well as all other organisms) are to united in one great system, but that different species, genera, or families of the same order inhabit different quarters of the world globe. If we now class the existing Mammifers, according to their range habitations & acc make, we will say, a three-fold division of existing mammifers, according to the amount of their differences in different countries; we shall divide the land into we will first say, three two two divisions, according to the amount of difference of, disregarding the numbers of, the terrestrial mammifers, inhabiting them; we shall have [illeg] Australia, perhaps probably

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A)

appears to me to be the same thing, as to know that illness is the road to death, [illeg] to look at illness as an ordinary event, nevertheless, to conclude that when the sick man dies, that his death has been caused by some unknown & violent agency.)⁋

 

(In a future part of this work we shall show that as a general rule [illeg] groups of allied though different species gradually appear & disappear,, one after the other, on the face of the earth, like the individuals of the same species: & we shall then endeavor to show the probable causes of this remarkable fact.)⁋

Chapter III

On the Geographical Distribution of organic beings in past & present times.

(For convenience sake, I shall divide this chapter into three sections. In the first, I shall endeavor to state the laws of the present distribution of existing beings.; in the second, that of extinct; [illeg] beings; and in the third section, I shall consider how far these laws are accord with the theory of allied species having a common descent.)

Section First.

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New Guinea, 2d South America, including the southern parts of Mexico, and 3d all the other continents. Temperate N. America, is in som from containing some S. American forms in some respects neutral, though I believe it certai is more allied (, as it certainly is in its birds plants, shells) to Europe, thus to S. America. If our division had been four-fold, probably Madagascar, though containing a very limited terrestrial Fauna, would have been the 4th division. If it had been five-fold, the southern part of Africa, & especially the southern part would have been our fifth division. These differences and the quadrupeds inhabiting in our three or five divisions

of the globe, cannot, it is well kown, be explained by corresponding differences in their conditions; how similar are parts of Tropical America & Africa; how similar parts of Chile & the Cape of Good Hope, & accordingly we find some analogical resemblences, thus both have monkeys, both large feline animals, both large Lepidoptera, & large- dung-feeding beetles;— both have Palms & epiphytes, & yet the essential differences between their productions, is as great as between those of the the temperate, though arid, plains of the Cape of Hope, & the temperate, grass-covered savannahs of La Plata. Consider the distribution of the Marsupialia, which are eminently characteristic of Australia & in a lesser degree of S. America;— when we reflect that those of animals of this division, feeding both on on animals & vegetables productionsmatter frequent

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New Guinea, and the rest of the world: if we make a three-fold division, we shall have Australia, S. America, & the rest of the world; I must observe that North America is in some repects neutral land, from possessing some S. American forms, but but I believe it is most more closely allied (as it certainly is in its birds, plants & shells) with Europe. If our division had been fourfold, we should have had, Australia, S. America, Madagascar (though inhabited by few mammifers & the remaining land: if fivefold, Africa, especially the southern extremity would have to be added, making A or separated from the remainder. These differences in the mammiferous inhabitants of the several main divisions

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New Guinea, and the rest of the world: if we make a three-fold division, we shall have Australia, S. America, & the rest of the world; I must observe that North America is in some repects neutral land, from possessing some S. American forms, but but I believe it is most more closely allied (as it certainly is in its birds, plants & shells) with Europe. If our division had been fourfold, we should have had, Australia, S. America, Madagascar (though inhabited by few mammifers & the remaining land: if fivefold, Africa, especially the southern extremity would have to be added, making A or separated from the remainder. These differences in the mammiferous inhabitants of the several main divisions

 

of the globe, cannot, it is well kown, be explained by corresponding differences in their conditions; how similar are parts of Tropical America & Africa; how similar parts of Chile & the Cape of Good Hope, & accordingly we find some analogical resemblences, thus both have monkeys, both large feline animals, both large Lepidoptera, & large- dung-feeding beetles;— both have Palms & epiphytes, & yet the essential differences between their productions, is as great as between those of the the temperate, though arid, plains of the Cape of Hope, & the temperate, grass-covered savannahs of La Plata. Consider the distribution of the Marsupialia, which are eminently characteristic of Australia & in a lesser degree of S. America;— when we reflect that those of animals of this division, feeding both on on animals & vegetables productionsmatter frequent

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the dry open or wooded plains, & mountains or forests of Australia, the humid impenetrable forests of New Guinea & Brazil; the dry rocky mountains of Chile, & green savannahs the grassy plains of La Plata Banda Oriental, we must confess look to some other cause, than the kind of nature of the country, for their absence absence in Africa & other parts quarters of the world.)

 

Furthermore it may be observed, that all the organisms inhabiting any country are not perfectly adapted to it, I mean by not being perfectly adapted, only, that some few other organisms can generally be found better adapted to the country, than some of the aborigines. We must admit this, when we consider the enormous number of horses & cattle, which have run wild during the last three centuries in the uninhabited parts of St. Domingo, Cuba Cuba & S. America; these [illeg] animals must have supplanted some aboriginal animals ones: I might, also, adduce the same fact in Australia, but perhaps it will be objected that 30 or 40 years has not been sufficient to test their powers of struggling & overcoming the aborigines. We know the Europæan mouse is driving before it, that of New Zealand, like the Norway rat has driven before it the old old English Rat species in England. Scarcely an island can be named, where casually introduced plants have not supplanted some of the native plants species: in La Plata, an introduced the Cardoon covers square leagues of country, on which S. American plants must once have grown: the commonest weed over the whole of India is an introduced Mexican poppy. The geologist, who knows that slow changes are in progress, [illeg] replacing land & water, will easily perceive that even if all the organisms of any country were once originally better the best adapted than the to it, this

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open & wooded plains

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could [illeg] hardly continue so during succeeding ages, without extermination, or changes in their qualities & relative

numbers.— constitutions or forms or qualities, first in the relative proportional numbers of the organisms inhabiting inhabitants of the country, & finally in their constitutions & structure, &

 

Inspection of a map of the world, at once shows that the five divisions separated according to the greatest amount of difference in the Mammifers inhabiting them, are likewise those most separated from each other by barriers, which mammifers could not cross: thus Australia is separated from New Guinea & some small adjoining islets only by a narrow & shallow strait, whereas the New Guinea & its adjoining islets are cut off from the East other East Indian Islands by deep water. These latter islands, or the other I may remark, which fall into the great Indio-Europæan (& if we make only these divisions,) African Asiatic and, group, are separated from each other & the continent only by shallow water, which we may believe within recent and where this is the case, we may suppose, from geologi=cal periods may have been united oscillations of levels, that generally there has been recent union.. South America including the southern part of Mexico, is cut off from the North America by the West Indies & the great table-land of Mexico, [illeg] except by a mere fringe of tropical forests land being left along the coast: it is probably owing owing, perhaps, to this fringe, that N. America possesses some S. American forms.;— Madagascar is entirely isolated. Africa is also to a great extent isolated, although it approaches by many points;— & by some

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lines of soundings shallow sea to Europe & Asia: Southern Africa, which is the most distinct in its mammiferous inhabitants., is separated from the northern points portion by the Great Sahara Desert, & the table-land of Abyssinia. That the distribution of organisms is related to the obsta barriers, stopping their progress, we clearly see by comparing the distribution of marine & land animals, terrestrial productions. The marine animals being different on the two sides of land, inhab tenanted by the same group of terrestrial animals; thus the shells are wholly different on the opposite sides of South America, as they are (?) in the Red Sea & Mediterranean. We can at once can see percieve, that the destruction of a barrier would would permit two geographical groups of organisms to fuse & blend into one. But the original cause of groups being different on opposite sides of a barrier can only be understood on the hypothesis of each organism having been created or produced in one spot or area & afterwards migrating, as widely as its means of transport & subsistence permitted it.)

 

It is generally found In terrestrial productions, the relation between their distribution & their [illeg] power of surmounting barriers is seen in I think, shown by the fact, which holds good in many cases, if not in most cases

 

⁋ (It is generally found, that where a genus or family group ranges over nearly the entire world, many of the species, composing the group the individual species have wide ranges: (A) Thus amongst mammifers the sp feline & [illeg] [illeg] (have wide ranges, & they are feline & canine genera are widely distributed, & many of the

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: on the other hand, where a group is restricted to any one country, the indi species composing it, generally have, generally restricted ranges in that country.

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The genus Mus is, I believe, an exception & a strong one to this rule.

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extensively distributed. The elephant & horse now have wide ranges & within a late geological range they had a very wide range. M. Gould informs me that this holds with birds, & the owl genus. May be instanced. (z) Back of Page

The individual species of Land & -fresh-water shells,, of butterflies, & cryptogamic plants have very wide ranges, & the so have the groups: Whether this holds with non-cryptogamic plants, I know not. On the ordinary theory of individual creations, the cause of this relation is not explicable; for why should it hold so generally, that because in two or three or four regions, species of a genus have been created in different regions, & & which have ranged far, should other quite distinct species be created in several other regions. Whether as a consequence of this relation or not, even in the same class, for instance with mammals the distribution of the organisms amount of difference in the different gen groups of the different great regions, is not same class, for instance in of the mammifers, is not the same in the different great regions; thus whilst S. America differs from Asia [words illeg] species; in her pigs, camels, & monkeys, the difference is generic or greater. Hence, Again, whilst southern Africa & Australia differ most more widely in their Mammalia, they present than Africa & S. America, they are more, (though very distantly), allied in their plants.)

(If we now look at the distribution of the organisms in any one of the above main divisions of the world, we shall it split up into many regions, with all or nearly all their species distinct, but yet partaking of common character. This similarity of type in the

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individual species have enormous ranges: the genus, mus, I believe, however, is one a strong great exception to the rule. Mr. Gould informs me that the rule holds with birds, as in the owl genus, which is mundane & many of the species range widely. The rule holds, also, with land- & fresh-water mollusca, with butterflies & very generally with plants. As instances of the converse rule, I may give that division of the monkeys, which is confined to S. America, and amongst plants, the cacti of confined to the same continent, the species of both of which have much generally narrow restricted ranges. On the ordinary of indivi theory of the separate creation of each species, the causes of these relations are not obvious; we can see no reason, when because several many allied species have been created in the several main divisions of the world, that generally several of these species should have wide ranges; but that allied species should have narrow ranges if all have been created in one division of the world. As the result of such & probably many other unknown relations, it is found that even in the same class of organisms, the different divisions of the world are charactereized by either by merely different in species, or in genera, or even

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families: thus S. America differs from Asia & Africa in her cats, mice & foxes only in species,

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individual species have enormous ranges: the genus, mus, I believe, however, is one a strong great exception to the rule. Mr. Gould informs me that the rule holds with birds, as in the owl genus, which is mundane & many of the species range widely. The rule holds, also, with land- & fresh-water mollusca, with butterflies & very generally with plants. As instances of the converse rule, I may give that division of the monkeys, which is confined to S. America, and amongst plants, the cacti of confined to the same continent, the species of both of which have much generally narrow restricted ranges. On the ordinary of indivi theory of the separate creation of each species, the causes of these relations are not obvious; we can see no reason, when because several many allied species have been created in the several main divisions of the world, that generally several of these species should have wide ranges; but that allied species should have narrow ranges if all have been created in one division of the world. As the result of such & probably many other unknown relations, it is found that even in the same class of organisms, the different divisions of the world are charactereized by either by merely different in species, or in genera, or even

[pinned insert:] families: thus S. America differs from Asia & Africa in her cats, mice & foxes only in species,

species; in her pigs, camels, & monkeys, the difference is generic or greater. Hence, Again, whilst southern Africa & Australia differ most more widely in their Mammalia, they present than Africa & S. America, they are more, (though very distantly), allied in their plants.)

(If we now look at the distribution of the organisms in any one of the above main divisions of the world, we shall it split up into many regions, with all or nearly all their species distinct, but yet partaking of common character. This similarity of type in the

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subdivisions of a great region, is equally well known with the dissimilarity of the inhabitants of the several great regions, but has been less often insisted, on, though more remarkable worthy of remark. Thus if we in, for instance, if in Africa or S. America, we go from South to North, or from lowland to upland, or from a humid to a dryer part, we find wholly different species of those same genera or groups, which genera or groups characterize the continent over which we are passing. In these subdivision we may clearly observe the as in the main divisions of the world, that sub-barriers divide different groups of species, although the opposite sides of such barriers may possess nearly the same climate, & may be in other respects nearly similar: thus it is with on the opposite sides of the Cordillera of Chile & in a lesser degree with of the Rocky Mountains. Deserts, arms of the sea, & even rivers, in other cases, form the barriers.— Mere space seems to be sufficient in many some several cases; thus Eastern & Western Australia, in the same latitude, with very similar climate & with similar soil, has scarcely a plant & few animals or birds in common, of those although all belong to the peculiar genera, which characterizing Australia. It is, in short, impossible to explain the differences of in the organisms inhabitants, either in of the main divisions of the world, or in of their subdivisions, subdivisions, of each of these, by the adaptation by the differences in their physical conditions, & by the

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adaptation to their of their inhabitants. Some other cause must be intervene. We can see, as I have [illeg] that the destruction of sub-barriers might would might would cause, as before remarked in the case of the main divisions, two sub-divisions to fuse into one; & we can only may must suppose that the original difference in the species on the opposite sides of barriers of sub-barriers is due to the creation or production of species in two distinct areas, from which they species have wandered wander, till stopped arrested by these such sub-barriers. But Although thus far is pretty clear; it may be asked, why, when species in the same main division of the world, were produced on opposite sides of a sub--barrier, or at the two ends of a wide space, under un when exposed to similar conditions, or again when and when exposed to widely different influences, as on the [illeg] alpine or and lowland tracts, as on an dry & arid or and humid sorts, as under in cold or and hot climates, were they have they invariably been formed on a closely similar type, & that type confined to that this one division of the world.— Why when an ostrich was produced created in the extreme southern part of America, was it formed on the American type type, instead of on the African or Australian types? Why when a hare-like & a rabbit-like animals were formed to live on the Savannahs of La Plata were they cre produced on the peculiar Rodent-type, of S. America, instead of on the true Hare-type of North America, Asia, & Africa? Why when

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Rodents, & burrowing Rodents, & a camel-like animals were formed to to tenant the Cordillera, were they formed on the same type with their representatives on the plains? Why were the mice & many birds, formed of the same type, but of different species on the opposite sides of the Cordillera, but exposed to a very similar climate & soil, created on the same peculiar S. American type? Why were the plants in Eastern & Western Australia though wholly different, as species formed on the same peculiar Australian type? Invariability The generality if not invariability of the rule in so many places & under such different circumstances makes it so striking highly remarkable, & seems to demand an some explanation.

 

If we now look to the character of organisms, inhabiting the inhabitants small islands, we shall find that those situated at a few hundred yards close to other land, have a similar fauna with that land; whilst those in open ocean at a considerable distance from from other land, often possess an quite almost entirely peculiar Fauna. St. Helena is a well known instance of this. The Galapagos archipelago is another a remarkable instance of this fact; here almost every bird, its one mammifer, its reptiles, land & sea shells & even fish are almost all peculiar & distinct species, not found in any other quarter of the world: so are the majority of its plants. But, although sutuated at the distance of between 500 & 600

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miles from S. American coast, it is impossible to even glance at a large part of it its Fauna,, especially at the birds, without at once seeing that they belong to the American type. Hence in fact, groups of islands thus circumstanced, form merely sub- small, but well defined subdivisions, of an described in the last paragraph of the main larger geographical divisions. But the fact is in many of these such cases far more striking; for taking the Galapagos Archipelago as one instance; in the first place, we see must feel convinced seeing that every island is wholly volcanic & bristled with craters, that in a geological sense the greater whole is of recent origin, comparatively with a continent; & as the species are nearly all peculiar we must confess that conclude that they probably have in the same sense recently been produced in the on this very spot; and, in the second place although in the nature of the soil, & in a lesser degree in the climate, there is a wide difference with the neighboring nearer part of the S. American coast, we see that the or inhabitants are, closely allied. have been formed on the same, closely allied type. On the other hand, these islands, as far as their physical conditions are concerned, are resemble far more closely the volcanic Cape de Verde volcanic Group, & yet how wholly unlike are the productions of these two archipelagoes. The Cape de Verde group, to which may be added the Canary islands, are allied to

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in their inhabitants, (of which many are mostly peculiar species) to the coast of Africa & southern Europe, in the precisely the same manner, as the Galapagos Archipelago is allied to America. We here clearly see that mere geographical proximity, without any relation affects without more than the relation of adaptations the character of a species. & which species are without any relation to their adaptation generally supposed to have been sep created produced by separate acts of the Creator. How many islands in the Pacific exist far more closely allied like in their physical conditions to Juan Fernandez, than this this islands is to the coast of [illeg] Chile, distant 300 miles; & yet why why then, except from mere proximity shd this island alone conta be tenanted by two very peculiar species of humming Bird, that form of bird which is so exclusively American? Many other similar instances cases might be adduced.—)

 

The Galapagos archipelago offers another, even more remarkable example of the class of facts we are here considering. Most of its forms genera are, as we have said, American, som many are of its forms. (I do not mean bats & & some of them genera, of them are mundane or found everwhere, and some are either quite or nearly confined to this archipelago. The islands are of absolutely similar composition, & exposed to to the same climate; most of them are in sight of each other, but are separated by deep ocean water & yet several of the islands are inhabited, each by peculiar species (or in some cases perhaps only varieties) of some of the genera characterizing the archipelago. So that

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the small group of the Galapagos islands typifies, the same laws in the distribution of its inhabitants, as a great Continent. How wonderful that two or three closely similar but distinct species of a Mocking Thrush, of Tortoise, of should have been produced on three neighboring & absolutely similar islands; & that these three species of Mocking Thrush, should be closely related to other species inhabiting forests, & plains, & mountains, both in the temperate & tropical parts wholly different climates and different districts of America, 600 miles distant, & only in America. No similar case, so striking as this of the Galapagos Archipelago, has hitherto been observed; & this difference of the productions in the different islands may perhaps be partly explained, by the depth of the sea between them (showing that they could not have been united within recent geological periods) [illeg], by by on the one hand the [illeg] currents of the sea sweeping straight through between them, — & by storms of wind being rare, by which seeds & birds could be blown from one island to another. Were There are, however, some similar facts, it is said that the different, though neighboring islands of the East Indian Archipelago are inhabited by some different species of the same genera; and at the Sandwich Group, each some of the islands have each their peculiar species of the same genera. of Plants.

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(Islands standing quite isolated within the intra-tropical region oceans have generally very peculiar floras, related, though feebly, (as in the case of St. Helena where almost every species is distinct) with the nearest continent: Tristan d' Acunha is feebly related, I believe, both to Africa & S. America, not by having species in common, but by the general character of its species. The floras of the numerous scattered islands of the Pacific are related to each other & to all the surrounding continents, but, it has been said, more to the with more of an Indio- Asiatic than American character. This is somewhat remarkable, as America is nearer to all the Eastern islands & lies in the direction of the trade-wind; but on the other hand all the heaviest gales f come from the Asiatic side. But even with the aid of these gales, it is not obvious on the ordinary theory of creation, how the possibility of migration, (without we suppose with extreme improbability that each species with an Indio-asiatic character has actually fr travelled from the Asiatic side shores, where such species do not now exist) explains this Asiatic character in the plants of the Pacific. This is no more obvious than that (as before remarked) than there should exist a relation between the creation of allied closely allied species having been created in one or several of the regions of the world,

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degree of relationship between the inhabitants of two points depends on their proximity, in relation to the nearness of these points, & nature of the intervening species. the completeness & nature of the barriers between them.

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character has actually travelled as is very improbable from that side of the Pacific, where these species are not now found, it is not obvious on the ordinary theory of creation how the possibility of such migration, explains the Indio-P[illeg] Asiatic character of the plants in the different islands of the Pacific. This is no more obvious than why because that, (as before stated) where there shd be a relation between two or three species of a genera in one quarter of the world having wider ranging powers, that or [illeg] other and other distinct species should of this genus inhabiting other quarters of the world. (are facts in this Paragraph Faithful) requires further researches)

(We will now turn to the Floras of mountain summits, These which are familiarly well known to differ from the Floras of lowlands. In certain characters, such as dwarfness of stature, hairiness &c all the different species from the most distant mountains frequently resemble each other,— a kind of analogy, like that, for instance, of certain other characters, which characterize plants growing under similar conditions, for instance the succulency of desert plants.— Besides this analogy, Alpine Flora plants present present some eminently curious facts in their distribution. In some cases, the summits of mountains, although separated immensely distant from each other, by are clothed by nearly absolutely the same plants identical species, which are likewise the same with those growing on the also likewise very distant arctic shores. In other cases, although few or none of the species are identical, they the plants of two mountains are far more closely related, far more so that the surrounding Lowland species. plants, surrounding the two elevated points. As Mountain--Summits

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and the fact of such most many of such species having restricted or wider ranges; ) in their once

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and the fact of many such species having wide ranges; and on the other hand, of allied species confined to one region of the world, having in that region narrow ranges.)

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of the species may be actually identical, they are closely related, whilst the plants of the lowland districts surrounding the two points mountains in question may will be wholly dissimilar. As mountain-summits

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and the fact of many such species having wide ranges; and on the other hand, of allied species confined to one region of the world, having in that region narrow ranges.)

(We will now turn to the Floras of mountain summits, These which are familiarly well known to differ from the Floras of lowlands. In certain characters, such as dwarfness of stature, hairiness &c all the different species from the most distant mountains frequently resemble each other,— a kind of analogy, like that, for instance, of certain other characters, which characterize plants growing under similar conditions, for instance the succulency of desert plants.— Besides this analogy, Alpine Flora plants present present some eminently curious facts in their distribution. In some cases, the summits of mountains, although separated immensely distant from each other, by are clothed by nearly absolutely the same plants identical species, which are likewise the same with those growing on the also likewise very distant arctic shores. In other cases, although few or none

[pinned insert:] of the species may be actually identical, they are closely related, whilst the plants of the lowland districts surrounding the two points mountains in question may will be wholly dissimilar. As mountain-summits

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, as far as their plants are concerned, are islands rising out of an ocean of land, in which the alpine plants species cannot live, nor across which is there any known means of transport, this fact appears directly opposed to the conclusions, which we have come to from considering the general distribution of organisms on continents & on islands.— I believe, however, this anomalous case admits as we shall presently see of an easy explanation. From what has gone before, We might have expected, that the Flora of a mountain-summit, wd have presented the same relation to the surrounding flora, of the surrounding country which any isolated part of a continent does to the whole, or an island with peculiar physical conditions, does to a continent the mainland, from which it is separated by a broad rather wide space of sea. distant a few hundred miles. This is the case within some of the species inhabiting some mountain-summits, (as in Tierra del Fuego, & Brazil??) of which the other species as characterized by have a close affinity or absolute resemblance, with species living on mountains immensely distant. This It is the case with all the species, inhabiting plants, clothing the summits of some mountains, which mountains it may be observed are particularly isolated; for instance all the species, are peculiar, but belong to American forms, characteristic of the continent in which they are situated, on the mountains of Caraccas, of Van Dieman's Land & I believe of the Neilgherries & of the Cape of Good Hope. (A)

In the islands, of which the lowland Flora is distinct, but allied to that of the nearest continent, the alpine plants of the summ its Mountain-summit, are generally sometimes or perhaps gen mostly, eminently

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On some other mountains, for instance in Tierra del Fuego & in Brazil, some of the species plants, though distinct species, are S. American forms, whilst others are allied to, or identical with speci the alpine species of Europe.

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peculiar & distinct; this is the case on Teneriffe, & in a lesser degree even on some of the Mediterranean islands.)

I suspect that much of the peculiarity of the flora of St. Helena is due to the greater part being [illeg] being alpine, & therefore being [words illeg] [illeg] doubly [illeg].) ⁋

(If all alpine Floras had been circumstanced characterized, like that latter, & like that of the Latter mountains of Caraccas & or of Van Dieman's Land &c, whatever explanation is possible of the general laws of Geographical distribution, would have applied to them. cases. But the apparently anamolous case, above alluded to, namely of the Mountains of Europe, of the White Mountains some in the United States & of the summits of the Himalayas, having many identical [illeg] species in common, & many closely allied conjointly with the Arctic regions, & many species though not identical, closely allied requires a separate explanation. The fact, likewise of all several of the species on the mountains of Tierra del Fuego, (& in a lesser degree on the mountains of Brazil) not belonging to American forms, but to Europæan those of inhabiting Europe, though so immensely remote, requires also also a separate explanation. Now we may with confidence affirm from the number of the then floating icebergs & low descent of the glaciers that within a period so near, that species of shells have remained the same, the whole of central & even partly southern parts Europe & of North America, as far as 42° s South (or perhaps of eastern Asia) possessed a very cold climate; and

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shores. If the arctic flora of that period was a nearly uniform one, as the present one is, then we ought now to find should have the same plants on these mountain-summits & on the present arctic shores. On this view, the nearly uniform arctic flora of that period must have been a widely extended one, even more so than the even the present one: but considering how similar the physical consitions must have always be of land bordering on perpetual frost, this does not appear a great difficulty; and

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therefore it is probable that the Flora of these districts was arctic the same as the present Arctic one,— as known to have been to some degree the case with the then existing sea-shells. & At this period the mountains must have been covered with ice, of which we have evidence in the surfaces polished & scored by glaciers. What then would be the natural & almost unavoidable inevitable effects of the gradual change into the present more temperate climate which has since supervened? ? The The ice & snow would disappear from the mountains, & as new plants from the more temperate regions of the south migrated northward, replacing the arctic plants, these latter would crawl up the now uncovered mountains & likewise be driven to the present arctic shores. No doubt this theory requires that once widely extended the the more a uniform arctic flora, once extended over even a considerably wider spaces, than even the present one does. But considering that this wide belt of land must have exposed to nearly similar conditions [illeg] May we not venture to suppose that the almost infinitely numerous icebergs, charged with great masses of [illeg] earth rock, soil & brushwood & often driven high high up on distant beaches might have been the means of widely extending distributing the seeds of the same species.)

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(At the same period when icebergs were transporting boulders in N. America as far as 36° South, where the Cotton-tree now grows; in S. America, in Latitude 42°, where the land is now clothed with forests taking taking an almost tropical aspect, with the trees bearing epiphytes & intertwined with

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I will only hazard one other observation, namely that during the first change from an extremely cold climate to a more temperate, all lands the conditions whether both on lowland & mountain, would be singularly favourable for the diffusion of all any the existing plants, which could live on land, just freed from the rigours of eternal winter, for it could possess no inhabitant; & we cannot doubt that preoccupation is the chief bar to the diffusion of plants. For, amongst many other facts, how else otherwise can we explain, the fact circumstance that the Floras plants on the opposite, though & similarly constituted, sides of a wide river in Eastern Europe wide rivers (in one case, on the eastern limbs of Europe at least,), (as I was informed by Humboldt) should be widely different; across which river birds, swimming quadrupeds & the wind must often transport seeds: — but we can only suppose that the plants already occupying the soil & freely seeding we must suppose check the germination of such occasionally transported

seeds.) ⁋.—

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therefore it is probable that the Flora of these districts was arctic the same as the present Arctic one,— as known to have been to some degree the case with the then existing sea-shells. & At this period the mountains must have been covered with ice, of which we have evidence in the surfaces polished & scored by glaciers. What then would be the natural & almost unavoidable inevitable effects of the gradual change into the present more temperate climate which has since supervened? ? The The ice & snow would disappear from the mountains, & as new plants from the more temperate regions of the south migrated northward, replacing the arctic plants, these latter would crawl up the now uncovered mountains & likewise be driven to the present arctic

[pinned insert:] shores. If the arctic flora of that period was a nearly uniform one, as the present one is, then we ought now to find should have the same plants on these mountain-summits & on the present arctic shores. On this view, the nearly uniform arctic flora of that period must have been a widely extended one, even more so than the even the present one: but considering how similar the physical consitions must have always be of land bordering on perpetual frost, this does not appear a great difficulty; and

with great masses of [illeg] earth rock, soil & brushwood & often driven high high up on distant beaches might have been the means of widely extending distributing the seeds of the same species.)

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(At the same period when icebergs were transporting boulders in N. America as far as 36° South, where the Cotton-tree now grows; in S. America, in Latitude 42°, where the land is now clothed with forests taking taking an almost tropical aspect, with the trees bearing epiphytes & intertwined with

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canes, the same ice-action was going on; can we then doubt but that at this period, the whole tropical parts of the two Americas possessed a more temperate climate. In this case, the alpine plants of the long chain of the Cordillera, & even of the lower chain transverse chains, connecting it with Brazil would have descended much lower, & we should there would have been a broad high-road, connecting those more temperate parts parts of North & South America, which were then parts: as the present climate supervened, [illeg] any points which formerly supported an alpine flora plants would loose them, & only a few of the highest points of the now temperate parts would retain them, & the extreme northern & southern points (then (formerly covered with ice) would be occupied with them or with a small remnant of them. The transverse chain of Chiquitos, would in a similar manner at that period have helped in connecting the Cordillera & the mountain highlands of Brazil. At present the two continent is halves of America, are almost divided, at the Isthmus of Panama & by the West Indian sea, & at the Isthmus of Panama, where the Cordillera of is very low, but some slight evidence can be adduced from the former range of certain extinct mammalia, showing that since about the time of ice-period, the two halves of America were more somewhere more intimately united, which might have favoured the passage of plants along the then temperate mountains, then temperate now [illeg] in climate. I will only further

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parts of North and South America, which were then temperate. frigid. As the present climate supervened, the plants, occupying the districts, in both which now are become in both hemispheres temperate & even semi-tropical, would be in both hemispheres, must have been driven to the arctic and antarctic regions; & only a few of the loftiest points of the Cordillera would can have retained their former connecting flora. The transverse chain of Chiquitos would in a similar manner, [illeg] during the ice-action-period have served as a less per connecting road though a imperf broken one for alpine plants from the Cordillera to the high-lands of Brazil. It may be observed that some though not strong reasons can be assigned for b[illeg] believing that at about this same period the two Americas were not so thoroughly divided as they now are by the West Indies & table-land of Mexico. I will only further

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canes, the same ice-action was going on; can we then doubt but that at this period, the whole tropical parts of the two Americas possessed a more temperate climate. In this case, the alpine plants of the long chain of the Cordillera, & even of the lower chain transverse chains, connecting it with Brazil would have descended much lower, & we should there would have been a broad high-road, connecting those more

[pinned insert:] parts of North and South America, which were then temperate. frigid. As the present climate supervened, the plants, occupying the districts, in both which now are become in both hemispheres temperate & even semi-tropical, would be in both hemispheres, must have been driven to the arctic and antarctic regions; & only a few of the loftiest points of the Cordillera would can have retained their former connecting flora. The transverse chain of Chiquitos would in a similar manner, [illeg] during the ice-action-period have served as a less per connecting road though a imperf broken one for alpine plants from the Cordillera to the high-lands of Brazil. It may be observed that some though not strong reasons can be assigned for b[illeg] believing that at about this same period the two Americas were not so thoroughly divided as they now are by the West Indies & table-land of Mexico. I will only further

might have favoured the passage of plants along the then temperate mountains, then temperate now [illeg] in climate. I will only further

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remark that the present singularly close similarity in the vegetation of the lowlands of Kerguelen Land & of Tierra del Fuego, though so far apart, may perhaps be explained by the (A) same causes, by which I have attempted to account for the [illeg]ooneruniform & widely diffused arctic flora, which has since been [2 words illeg]the mountains of Europe & to the shores of existing arctic oceans.—

 

(Finally I think there is sufficient weight in the foregoing we may safely grant from the foregoing facts and reasoning, to allow make us grant, that the anomalous similarity in the vegetation of certain very distant mountain summits is not in truth opposed to the former conclusion, of the intimate relation, subsisting between proximity in space (in relation to accordance with the means of transport in each class) & the degree of affinity of the inhabitants of every any two country. In the case of several quite isolated mountains, we have seen that the general law holds good.) I will only add, that the changes of climate, of which [illeg] have just alluded to the evidence, in the case of these isolated mountains, would destroy some species, affect the constitutive relative numbers of others & require the production or creation of some new forms, in precisely the same manner, as all similar, or any kind of change would affect all the inhabitants, of an island or any isolated point, [words illeg] existing organisms, better adapted to the new conditions, could not freely immigrate.

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dissemination of seeds, during this same cold period, by means of icebergs, as before alluded to.) ⁋

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(As the first of the same species of plants having been found on mountain-summits immensely remote, has been one the chief cause, I believe of the belief of same species having been contemporaneously produced or created created at two different points, I will here make a on[illeg] briefly digression on discuss this subject. On the ordinary theory of creation, we can see no reason, why on two similar mountain-tops, summits, two similar species may not have been created; but the opposite view independently of its simplicity, has been generally recieved, owing to from the analogy of the general common distribution of all organisms, in which, as just abov shown, in this chapter we almost always find that great & continuous barriers divide separate two sets of species, distinct series; & we are naturally led to suppose that the two sets series have been separately created. When taking a more limited view we see a river, with a quite similar country on both sides, with one side well stocked with with a certain animal & with on the other side without not one, individual of the species, as is the case with the Bizcacha on the two opposite sides of the Uraguay Plata, we are at once led to conclude that the Bizcacha was produced on some one point or area, on one, namely the Western side of this river. Considering our ignorance of the many strange chances of diffusion, by birds, (which occasionally wander to immense distances) & quadrupeds swallowing seeds [illeg] & of [illeg] ova (as in the case of the flying water-beetle which disgorged the eggs of a fish) & of whirlwinds carrying seeds & animals into strong upper currents (as in the case of volcanic ashes & showers of hay, grain, & fish) & of the possibility of species surviving having survived for short periods at intermediate spots; and considering our knowledge of the great changes, which have taken place from subsidence & elevation in the surface of the earth, & of our ignorance of the greater changes which may have taken place, we ought to be very slow in admitting the probability of double

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creations. In the case of plants on mountain-summits, I think, I have shown how almost necessarily they plants on them must would under the past conditions of the northern hemisphere be as similar, as is Flora of as are the plants on the present arctic shores; & this ought to teach us a lesson of caution.) ⁋

(But the strongest argument against double creation may be drawn from the considering the distribution case of mammifers, in which from their size nature & from the size of their offspring, we are less dependence their the means of their distribution are more in view. There are no cases, where the same species is found in very remote localities, except where there is a nearly continuous belt of land: in The Arctic region, perhaps offers the strongest exception, & here we know that animals are transported on icebergs. The Ibex on distant the mountain summits of Europe might have been driven to them, with the alpine plants, during the changes of climate already described. The same mammifer is sometimes found on small not distant islands near a coast & on the mainland, The cases of lesser difficulty may all receive a more or less simple explanation; I will give only one instance; the nutria, I believe, on the Eastern coast of S. America lives only exclusively in Fresh-water rivers, & I was much surprised how they could have got into rivulets, widely apart on the coast of Patagonia; but on the opposite coast, I found, these quadrupeds living exclusively in the sea; & hence their migration along the Patagonian coast is not surprising. There is no case, of an animal the same mamifer being found on an island far from the coast & on the mainland, as happens with plants; on the idea of double creation, it would be strange, if the same species of several plants should have been created in Australia & Europe & no one instance of the same species of Mammifer having been created at or aboriginally existing in two half as nearly remote & equally

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isolated points. It is more philosophical, in the such cases, as of the same plants being found in Australia & Europe to admit that we are ignorant of the means of transport.— I will allude only to one other case, the Mydas, found an alpine animal found only on the distant summits peaks of the mountains of Java; who will pretend to deny that during the ice-period of the Northern & Southern hemisphere, & when India is believed to have been colder the climate might not have permitted this animalto haunt a lower country, & thus have passed along the ridges from summit to summit.— Mr Lyell, has further observed, that, as in space, so in time, there is no reason to believe that after the extinction of a species, the exa self-same form has ever reappeared. in this world.— I think then, we may, notwithstanding the many cases of difficulty, conclude with some confidence, that every species has been created or produced on some one a single point or rather area.) ⁋.

(The last fact in the geographical distribution, which as far as I can see anyway concerns the origin of species, relates to the absolute number, of classes and nature of the organic beings inhabiting different tracts of land. Although every species is well adapted (but not necessarily always the best better adapted than every other species, as we have seen in the great increase of introduced species to the country & station, it frequents; yet it has been shown that the entire difference of the species in many all distant countries, cannot possibly be explained by the difference of the physical conditions of these countries. In the same manner, I believe, neither

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the number of di the species, not the nature of the great classes to which they belong, can possibly in all cases be explained by the conditions of their country. which they [illeg] inhabited by them. New Zealand, a linear island, stretching over nearly [illeg] degrees about 700 miles of latitude, with forests, marshes, plains, & mountains reaching to the limits of eternal snow, has far more diversified habitats that an equal area [illeg]e at the Cape of Good Hope, & yet I believe in such an area there are of Phanerogamic plants five five to ten times the number of species. Why on the theory of absolute creations, should this large & diversified island only have from 400 to 500 D (? Dieffenbach) phanerogamic plants, & why should the uniformity, Cape of Good Hope, characterized by the uniformity of its scenery, swarm with more species of plants, than possibly any other quarter of the world? Why on the ordinary theory should the Galapagos islands swarm abound with terrestrial Reptiles, & why should many equal sized islands in the Pacific be without a single one or with only one or two species? Why should the great island of New Zealand, or those many smaller be without one mammiferous quadruped, except the mouse & that probably introduced with the aborigines? Why should there not exist one island (it can be shown, I think, that the mammals of Mauritius & St Jago have all been introduced) in the open ocean possess a mammiferous quadruped? Let it not be said that quadrupeds cannot live in islands; for we know that Europæan mamm cattle for certain long periods horses & pigs during a long period have or do run wild in the West Indian & Falkland

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that quadrupeds are more slowly created, & therefore [Lesser] that the oceanic islands generally of volcanic origin formation are of too recent origin to possess them; for we know that the persistance new forms of quadrupeds succeed each other quicker than Mollusca or Reptilia. Nor let it be assumed,

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islands: pigs & pigs at St. Helena; goats at Tahiti; apes in the Canary Islands cats dogs at in the Cuba, cats at Ascencion, Rabbits at Madiera & the Falkland monkeys at St Jago & the Mauritius, & even Elephants during a long time in one of the very small Sooloo islands; & Europæan mice on very many of the smallest islands, far from the habitations of Man. Now let it be assumed, (A) -Back of page though such an assumption would be no explanation, that quadrupeds cannot be created on [illeg] the [illeg] small islands, for islands not lying in mid-ocean do possess their peculiar quadrupeds; thus many of the Falklands smaller islands of the East Indian Archipelago possess quadrupeds; as does Fernando Po on the west coast of Africa; as the Falkland Island possesses a peculiar wolf-like fox; & as so do do the Galapagos Archipelago possesses islands, a peculiar mouse of the S. American type. These two last are the most remarkable cases, with which I am acquainted in as much as the islands lie further from other land. It is possible that the Galapagos mouse may have been introduced in some ship from the S. American coast, as the (though the species is at present unknown there) for the aboriginal species soon haunt the goods of men, as I noticed in the roof of a newly erected shed in a desert country, south of the Plata. The Falkland Island, though abo between 200 & 300 miles from the S. America coast, may in one sense be considered as intimately connected with them it, for it is certain, that formerly many icebergs, loaded with boulders were stranded on its southern coast, & the old canoes

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which are now occasionally now stranded on show that the currents set from Tierra del Fuego ; : this, however, would not aid the Creation [illeg] without ha we to suppose, This fact, however, does not explain the presence of the Canis antarcticus on the Falklands Islands, without we suppose that it formerly lived on the main-land & became extinct there, but survived on these islands, to which, like the it was borne (as happens with its northern congener, the common wolf) it was borne on an iceberg; but it makes removes the anomaly of an island, thus far in appearance effectually separated from other land, having its own species of quadruped, & makes the case like that of Java & Sumatra, each, having their own Rhinoceros. (A) Back of Page

Section II Second Geographical distribution of extinct [illeg] organisms animals organism

I have stated that if the land of the entire world be divided into, we will say, three sections, according to the [illeg] differences of the terrestrial mammifers inhabiting them, we shall have th[illeg] three unequal divisions of (1st) Australia & its dependent islands. (2d) South America, (3d) Europe, Asia & Africa. If we now look to the Mammifers, which inhabited these three divisions, during the later Tertiary periods, we shall find them almost as distinct as at the present day, & each intimately related, in each division, to the existing forms in that division. This is wonderfully the case with the several fossil Marsupial genera in caverns New South Wales, & even more wonderfully

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Before summing up all the facts, given in this section on the present distribution of organic beings, & endeavoring to see how far they admit of explanation, it will be admissable convenient to state such facts in the past geographical distribution of extinct organic beings, as seem to concern the theory of descent.—) ⁋.—

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so in South America, where we have the same peculiar group of monkeys, of a guanaco-like animal of many rodents, of the marsupial Didelphys, of Ed Armadillos & other Edentata. This last family is at present very characteris of S. America, & in a later Tertiaty epoch, it was even more so, as is shown by the numerous enormous animals of the Megatheroid family, some of which were protected by an osseous covering armour, a gigantic like that, but on a gigantic scale, of the Armadillo. Lastly over over Europe, the remains of the Elephant, Hippotamus, Rhinoceros, & Hyæna, during the later periods, clearly belong to the African division of the World. several deer, oxen, Bears, Foxes, Beavers, field-mice, show a relation to the present inhabitants of this subdivision region; & the contemporaneous remains of the Elephant, Rhinoceros, [illeg], Hippotamus, Hyæna, show a relation with the grand Africo-Asiatic division of the World. In Asia the fossil Mammifers of the Himalaya, (though mingled with forms long extinct in Europe) are equally related to the existing new forms of the Africo-Asiatic division; but especially to those of India itself. As the gigantic, & now extinct quadrupeds of Europe, have naturally excited more attention than the other & smaller & more remains, the relation between the past & present mammiferous inhabitants of Europe has not been attended to. But in fact the present mammifers of Europe are at present nearly as much Africo-asiatic, as they were formerly: Europe neither now nor then possessed peculiar groups

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as does Australia & S. America. The extinction of certain prominent forms in one quarter, [illeg] the tert equally related does not make the remaining mammifers of that quarter less related to the other parts quarters of a its own great division of the world. Though Tierra del Fuego possesses only five terrestrial mammifers a fox, three Rodents & the Guanaco; no one, as these all belong to the South American types, though but not to the most characteristic forms, would doubt for one minute classifying this district with S. America; & if fossil Edentata, Marsupials, & Monkeys were to be found in T. del Fuego, the it wd not make this district more truly, though more prominently S. American. So is it with Europe, and as far as is known in with Asia the lately past & present mammifers all belong to the Africo-Asiatic division of the world. In every case, I may add, what the forms which a country has, is of more importance in geographical arrangement, then what it has not.) ⁋.

⁋ (We find some evidence of the same general fact in the relation of the recent & Tertiary sea-shells in different the different main divisions of the marine world.)

⁋ (This general & most remarkable relation between the lately-past & present mammiferous inhabitants of the three main divisions of the world, is precisely the same kind of fact, as the common relation between the regions of the same main, in which regions, not one species is the same. different sub-regions [illeg] in which the species are not identical, of any one of their main divisions. As we usually associate great physical changes in the total extinction of one race series of beings, & its succession by another series, this identity of relation between the past & present races of beings, in the same main division, quarters of the globe, is more striking than the same relation between

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existing beings in different parts of the same grand division sub-regions:; but in truth we have in truth no reason for supposing that a change in the conditions has in any of these cases supervened, greater than that now existing between the temperate & tropical, or between the high-lands & low-lands of the same main divisions, now tenanted by related beings. Finally then we clearly see that in each main division of the world, the same relation holds good between its inhabitants in time as over space.—

If, however, we look closer we shall find that even Australia, in possessing a terrestrial Pachyderm, was so far less distinct from the rest of the world, than it now is; so was S. America, in possessing, the Mastodon, Horse, HyænaN. America, as I have remarked is , and Antelope. now in its Mammifers in some respects neutral ground between S. America & the great Africo-Asiatic division; formerly in possessing the horse, Mastodon, Megatheri & three Megatheroid animals it was more nearly related to S. America, but in the horse & Mastodon & likewise in the having the Elephant, oxen, sheep, & pigs, it was as much, if not more, related to the great Africo-asiatic division.— Again Northern India was much more closely related to S (in having the Giraffe, Hippotamus, & certain musk-deer) to southern Africa, than it now is; for Southern Africa, now deserves, if we divide the world into four more than three five parts, to make

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one division by itself (A)

⁋(If we now turn to look at the distribution of sea-shells, we find the same variations in range. The Red Sea & Mediterranean, and the Eastern & western sides of S. America were more nearly related than they now are. In Europe different parts of Europe, during the Miocene period, the sea shells seem to have been more different than at present, & during the Cretaceous still less like; whereas during this same Cretaceous period, the shells of India & Europe were more like. But going further back to the Cretaceous Carbonaceous period in N. America & Europe the productions were much more like than they now are. These facts harmonise with the conclusions, drawn from the present distribution of organc beings, for we have seen, that from species being created in different points or areas, the existence or formation of a barrier would cause or make two areas distinct geographical areas; & the destruction of a barrier would permit their diffusion. And as these slow long continuous geological changes would must both destroy & make barriers, we might expect the further we looked backwards, the less defined more changed should we find the existing present distribution. This conclusion is of worthy of attention; because finding in widely different parts of the same main division of the world

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Still considering mammifers, if we turn to the dawn of the Tertiary period, we must from our ignorance of other parts, portions of the world, confine ourself to Europe, & at that period in the presence of Marsupials & Edentata we behold an entire blending of those forms, which now eminently characterize Australia & S. America.) ⁋.

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groups of related, but distinct related but

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and in volcanic islands formed near it, groups of distinct, but related species;— and finding that the [illeg] same Singular a singularly analagous relation in the character of living b holds good with respect to the beings of in past times, when none of the present species were living, a person might tempted to believe in some mystical relation between certain areas of the world, & the production of certain organic forms; but we now see that such an assumption would have to be complicated by the admission, that the such a relation, though holding good for long revolutions of years, is not truly persistent.) ⁋ (I will only add one more observation to this section: Geologists finding in the shells & corals most remote period, with which we are acquainted, namely in the Silurian period, that the shell & corals other marine productions, seen in N. & South America, in Europe, & even southern Africa & East Western Asia, are much more similar, than they now are at these distant points, have appear to have imagined that in those ancient times the laws of geographical distribution were quite different than what they now are: but we have only to suppose that the great continents were almost [illeg] were less almost were extended East & West, & thus did not cut divide the inhabitants of the temperate & tropical seas, as now did the continents now do, & it would be probable that the inhabitants of the seas seas would be

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much more similar than they now are. In the immense space of ocean, extending from the East coast of Africa to the eastern islands of the Pacific, [illeg] which space is connected either by lines of tropical coast, or by islands not very distant from each other, we know (Cuming) that many shells, perhaps even as many as 200, are common from to the Zanzibar Coast, the Phillippines, & the eastern islands of the Low or Dangerous Archipelago in the Pacific. This space equals that from Pole the Arctic to the Antarctic Pole!— (A)

Many fish, I may add, are also common to the Pacific & Indian oceans.)

Let us sum up the several facts, now given in the past & present geographical distribution of organic beings. In a previous chapter, it was shown that species are not univerally exterminated & are slowly produced: we now see that they are each species is probably only once produced on one point or area; & that each diffuses itself, as far as barriers & means its conditions of life permit. If we look at any one main division of the land, we find many in the different parts, whether exposed to different to conditions, or exposed to the same conditions if separated by [illeg] narrow barriers, or by (wide spaces fully tenanted by other organisms beings being a sufficient barrier) many groups of species, wholly or nearly distinct as species.

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Pass over the narrow space of South America quite open ocean from the Dangerous Archipelago to the West Coast of S. America & every shell is different: pass over the narrow space of S. America, to its eastern shores & again every shells is different!

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nevertheless these species are intimately related. We find the inhabitants of islands, rel though being distinct as species, similarly related in the same manner to those to the inhabitants of the nearest land continent: we find in some cases that even the different islands of one such group, intimately are inhabited by species distinct, though intimately related together, one to another, & to those of the nearest continent;— thus typifying the distribution of organic beings over the whole world. We find the Floras of mountain summits, either very similar, which admits, as shown of a simple explanation, or very distinct, but related to the Floras of the surrounding region; & in this case the Floras of two mountains-summits, although exposed to qu closely similar conditions, will be very different. We find the Floras of On the mountain- summits of islands characterized by peculiar Faunas, the plants are apt to be often eminently peculiar. The dissimilarity of the organic beings inhabiting some nearly similar countries, is best seen, by comparing the main divisions of the world; in each of which some districts may be found very similarly exposed, yet the inhabitants are wholly unlike; far more unlike than those in very dissimilar districts in the same main division. We see this strikingly in comparing two volcanic archipelagos, with nearly the same climate, but situated not very far from two different continents, in which case, then how are their inhabitants are totally unlike. In the different main divisions, the amount of difference of the organisms, even in the same class, are is widely different; in some genera families, each main division has only [illeg] distinct species, in others quite distinct genera,. The distribution The effects of barriers in. The distribution of aquatic animals organisms is very different from terrestrial animals organisms, & necessarily so, from the barriers to their progress, being quite unlike. & even in terrestrial & aquatic organisms, the distribution according to their classes & & some degree to their means of transport is different. The nature of the conditions in isolated districts will not explain the number of species inhabiting it; nor the absence of one class, or the presence of another class. We find that terrrestrial mammifers are not present on islands far removed from other land. We see that in two regions, all that the

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species though distinct are more or less related, according to the greater or less possibility of the transportal either in past or present times of species from one to the other, although we cannot admit that all the actual species have all been transported from one the first to the other second region, & since have become extinct in the second: we see this law, in the presence of the fox on the Falkland Islands, in the Europæan character of some of the plants of Tierra del Fuego, in the Indio-asiatic character of the plants of the Pacific, & in the circumstance of those species generally genera, which range widest, of those having different many species in the different countries with wide ranges; & those genera with restricted ranges having species with restricted ranges. This greater [illeg] affinity of the organisms on the opposite sides of a barrier in the same main division of the world, being as just shown greater far closer, than in any two districts in two different of the main divisions, seems, also, to result from no the barriers within the same main division of the world not not being probably or probably not having been in past times been, nearly so impassable, as the greater barriers between the main divisions of the world. Finally we find in each of the main great main divisions of the land, & probably of the water sea, that the existing organisms are wonderfully related to those last or lately extinct., (at a time when probaby not as far as we know one of our the present inhabitants [illeg] classes were living ) in the same manner but more wonderfully, as the differently conditioned regions of the [illeg] main divisions are related Looking further backwards we see that the past past geographical distribution of organic beings was not the same, different from the present & indeed considering, that geology shows that all our land was once under water, & that where water now extends, land is forming, this could be hardly have been possible. Now these several facts, though evidently all more or less connected together, must by the Creationist (though the geologist may explain some of the anomalies) be considered as so many ultimate facts. He can only say that it so pleased the Creator, that the organic beings of Tierra del Fuego, should have some Patagonia the plains, deserts, mountains, tropical & temperate forests of S. America,

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affinity with those of Brazil, & that those should all have some affinity together; that the inhabitants of the Galapagos archipelago should, have a similar affinity with be related to those of Chile; but and that some of the species on the similar-ly constituted islands of this Archipelago, should have strong affinity but though most closely related should be distinct; that all [illeg] its inhabitants should be totally unlike those of the similarly volcanic, tropical & arid Cape de Verde & Canary Islands;— that the plants of the summit of Teneriffe should be eminently peculiar;— that the diversifyed isld of New Zealand should have not many plants & not one or only one Mammifer, that all the Mammifers of S. America, Australia & Europe should be clearly related to their ancient exterminated prototypes; which have and so on with the other facts. But it is absolutely opposed to every analogy, drawn from the laws governing imposed by the Creator on inorganic Matter, that connected & even trivial facts, when connected, should be considered as ultimate, ones, & not the direct consequences of more general laws.

Section III Third. An attempt to explain the foregoing laws of geographical distribution, on the theory of allied species having a common descent.

First let us recall the circumstances most favourable for variation, under domestication, as given in the Part First First Chapter;— viz (1st) a change or repeated changes in the conditions (perhaps with excess increase of food) to which the organism has been exposed, (perhaps with increase of food continued through several (true i.e. true (i.e. not by buds, bulbs, or division) generations: 2nd steady selection of the slight variaties, thus generated, tending towards some form or end, 3d isolation as perfect as possible of such varieties, that is the preventing their crossing with other forms; this latter condition applies to all terrestrial animals, to most if not all plants, & probably perhaps to even to most or all aquatic organisms. It may will be [illeg] convenient here to show the advantages of isolation in the formation of a new breed, by comparing the progress of two people persons (to neither of whom let time ,as to the [illeg] is of was of no be any consequence), as it endeavoring to select & form some very very peculiar new breed; let one

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of these have to work on the great vast herds of cattle on the plains of La Plata, & the other on the a small stock of 20 or 30 animals in an island. The latter might have to wait centuries (by the hypothesis of no importance) before he obtained a "sport" approaching to what he wanted, but when he did & saved the greater number of its offspring, & their offspring again, he might hope that this his whole little stock in the island would be in some degree affected, so that by continued selection he might gain his end. But on the Pampas, though the man might get his first approach sooner, how hopeless would it be to attempt by saving its offspring, amongst so many of the common kind, to affect the whole body: the effect of this one very peculiar sport wd be quite lost, before he could obtain a second original sport of the same kind If, If, however, he could separate a small number of cattle, with some of the offspring of the desirable "sport", he might hope, like the man on the isld to effect his end. If there be organisms organic beings, of which never cross with others two individuals never unite, then simple selection, whether on continent or island would be equally serviceable to make a new & desired desirable breed; & if this was very superior it new breeds might be made, from the great & geometrical rates tendency powers of propagation, in surprisingly few years to beat out the old breed; as has happened, notwith==standing crossing, where good breeds of dogs & pigs have been introduced into a limited country, for instance into the islands

of the Pacific.) ⁋

Let us now take the simplest case of an islet formed upheaved by the volcanic or subterraneum forces in the a deep sea, at such a distance from other land, that only a few organic beings at rare intervals were transported to it, whether wafted borne by the sea (like the seeds of plants to Coral-reef) or by hurricanes, or by floods or on rafts, or in the roots of large trees, or the germs of one plant or animal attached to another or in the stomach of some other animal, or by the intervention (in most cases the most probable means) of other islands, since sunk or destroyed. The seeds of sea-borne plants would first arrive as It may be remarked that when one part of the earth's crust is raised, it is probably the general rule, that another part sinks. Let this island go on slowly, century after century, rising foot by foot;

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(A) it might, also, easily happen that some of the species, on an average, might obtain an increase of food or food of a more nourishing quality.—

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& in the course of time we shall have, instead a low point small mass of rock, lowland & highlands,— moist woods & dry tracts [illeg] bare spots, various soils marshes, rivers streams & pools: under water on the sea-shores, instead of a rocky rocky steeply shelving coast we shall have bays in some parts, with mud, sandy-beaches, & rocky shoals. The is formation itself of the island will must often slightly affect the climate. itse It is impossible that the first few transported organisms could be perfectly adapted to all these stations: it will be a chance if those successively transported will be so adapted. The greater number would probably have come from the lowlands of the adjoining nearest country; & probably not even all these would be so perfectly adapted to the new islet when whilst low, & all the whole exposed to coast-influences. Moreover, as it is certain that all organisms are nearly as much adapted in their structures to the other organisms of the inhabitants of their country, as they are to its physical conditions; so the mere fact, that only a few beings, & these taken in great degree by chance, were in the first case transported to the islet, would in itself greatly modify their conditions. As ,also, the island was continued rising we might perhaps, also, expect an occasional, though rare new visitant; & I repeat, that even one new being must often affect, beyond our calculation, by on occupying the room or taking part of the subsistence of another ( & ( & this again, from another & so on), several or many other organisms. Now as the first transported & any occasional successive visitants spread or tended to spread over the growing island, they would undoubtedly be exposed through several generations to new & constantly [illeg] new & varying conditions: (A)

According then to every analogy, with what we have seen takes place in every country with nearly numerous infinitely diversified & numerous every organic being under domestication, we might expect that some of the transported organisms inhabitants of the island would "sport" or fast transmit to their offspring such exact

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likenesses of themselves to their offspring. or have their organization rendered plastic. As the number of species the inhabitants are comparati few comparatively supposed to be few & as all these cannot be so well adapted to their new & revarying conditions, as they were in their native country & habitat, we musn't cannot believe that every place or office in the œconomy of nature is so well filled, as on a continent where the number of aboriginal species are which may be considered as comparatively aboriginal, is far more numerous greater & where they consequently hold their place a more strictly limited place, against a far severer struggle. We might therefore expect on our island, that now & then a although very many, slight variations, (although other & numerous similar variations no were of no use to the plastic individuals thus characterized, every now & then varying, yet that yet that occasionally in the course of a century, one might be born, of which the structure or constitution in some slight degree would tend to allow it the species better to fill up some office in the insular œconomy, & to struggle against other species. If such were the case, the individual & its offspring would obviously have a better chance of surviving & beating out its parent form; & if (as is probable) it & its offspring crossed with the common common parent form, yet the number of individuals being not very great, there would be a better chance of the new & more serviceable form vari form being passed in some slight degree preserved; & the struggle for existence & continual natural selection would go on preserving selecting such individuals, until a new race or species were formed.—

Either few or all only a few, or even all the original species on the island ev of the conditions were the original the first visitants to the island, might become selected & altered, modifyed,— according as the physical conditions of the island & those arising resulting from the kind & number of the other transported species were different & continued varying from those of the parent-country,— according to the difficulties offered to fresh immigration,— and according to the length of time, since the first spe

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inhabitants were introduced. Yet It is obvious, that whatever was the country, generally the nearest, from which the first tenants were transported, they inhabitants of the island would show an affinity, even if all had become changed modified, would show (when not altered in an extreme degree) an affinity with the country of to the natives of that country. & lesser Thus we can at once see understand the cause & meaning of the affinity of the Fauna of the Galapagos islands & with that of the coast of S. America; & consequently why the the inhabitants of these islands, show not the smallest affinty with those inhabiting other volcanic, islands with a very similar climate, near the coast of Africa.

 

To return once again to our island, if by the continued action of the subterranean forces, other neighboring islands were formed; these would generally be tenanted stocked by the same the inhabitants as of the first island, or by a few new immigrations immigrants from the neighboring main-land; but if great considerable obstacles were opposed to any communication between the terrestrial productions of these islands, & their conditions were different (perhaps only by the number of different species on each) a form transported from one island to another might become altered, in the same manner as one from the continent & we should have each several of the islands tenanted by representative races or species on the several islands, ( as is [illeg] in so wonderfully the case of with the different islands of the Galapagos islands) archipelago. But nearly all would be related show one similar relation to the inhabitants of the nearest & parent main-land. As the islands became

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mountainous, if mountain-species were not introduced, as could would rarely happen, a greater amount of variation & selection would be requisite to adapt the lowland species which originally came from the lowlands of the mainland nearest continent, to the mountain-summit, than to the lower lands of the islands districts of our islands:; for the lowland species would have first to become fitted to struggle against other species & other conditions, on the midland slopes of the island & afterwards to on the alpine summits when formed,; & hence we can understand, why the Fauna of insular mountain summits are, often as in the case of Teneriffe eminently peculiar. Putting on one side the case of the uniformly lowland flora & [illeg] same, widely extended species being driven up to the this mountain summits, during a change of climate from cold to warm temperate; we can also see why in other cases the floras of such mountain summits, (or as I have called them islands in a sea of land,) should be tenanted by peculiar species, but related to those of the surrounding low lands, as are the inhabitants of a real island to the nearest continent.)

(Let us now consider the effect of a change of climate or of other conditions on a continent & on an isolated islands, without a change of level. On the a continent, the chief effect would be changes of in the numerical proportion of the individuals of the different species; for whether the climate became warmer or colder, dryer or damper, more uniform or extreme, in a large continent some species will be are at present adapted to these its various parts diversifyed districts; if, for instance, it became colder cooler, species would migrate from its more temperate parts & from its higher land; if damper, from its dryer damper regions &c. On an isolated island, however, with more limited & less diverse stations & with fewer species, such changes

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From such islands, [illeg] these new forms would might would occasionally, & from the formative be transported by accident, or emigrate through the formative [illeg] long-continued geographical changes, & so thus become diffused.)

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would much sooner affect the adaptive [illeg] constitutions of some of its inhabitants. In this case, therefore, & still more in rising, as we have seen, during a gradual elevation elevation & enlargement & consequently the necessary production of new stations from the from its gradual elevation & enlargement, of, elevation & enlargement of the land, an island must would be a far more fertile source, as far as we can judge, of new forms, than a continent. (A)) (A)

(But if we look to the origin of a continent, every geologist will admit that have in most cases, they it will have first existed as separate islands, gradually increasing in size; & therefore all that which has been said concerning the probable changes of the forms tenanting a small archipelago, is applicable to a continent in its early state. Furthermore, a geologist, who reflects on the geological history of Europe, the only region well known, will admit, that it has been many times depressed, raised & left stationary. During the sinking of a continent, & the probable generally accompanying changes in climate, the effect on the species, ( except in their numerical proportions & [illeg] the extinction of some or many (from the lessening of rivers, subsidence of marshes, highlands becoming low [illeg]) would be small. until As soon as, however, the continent became divided into many isolated portions or islands, preventing free immigration from one part to another & with considerable changes of climate the effect on the species would be greater. But let the now island- broken continent, forming islands forming isolated islands, begin to rise, in[illeg] & new stations thus to be formed, exactly as in the

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Some Single Islands, standing in the open ocean at least one, namely St. Helena, has so peculiar a flora, that, I believe, it is related to no one continent more than another. Tristan d' Acunha, standing in the Southern Atlantic midway between Africa & S. America, is, I believe, feebly related to both these continents. It is said that the islands of the Pacific, (excluding of course, those sea-borne plants which tenant coral-reefs) are very closely related; if the relation be only that most of the species belong to the same genera, it is only what [text excised] the analogy of one

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On a small & isolated island, however, with few species & these not adapted to many much diversifyed conditions, such changes, would, instead of merely increasing the number of certain species already [illeg] living somewhere found on the large tract of land adapted to such changed new conditions, & decreasing the number of other species, would be apt to affect the adaptive constitution of some of the insular species: thus if the island became damper, it might well happen that there were no species living in any part of it, adapted to the consequences resulting from more moisture. In this case, therefore,

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On a small & isolated island, however, with few species & these not adapted to many much diversifyed conditions, such changes, would, instead of merely increasing the number of certain species already [illeg] living somewhere found on the large tract of land adapted to such changed new conditions, & decreasing the number of other species, would be apt to affect the adaptive constitution of some of the insular species: thus if the island became damper, it might well happen that there were no species living in any part of it, adapted to the consequences resulting from more moisture. In this case, therefore,

& still more in rising, as we have seen, during a gradual elevation elevation & enlargement & consequently the necessary production of new stations from the from its gradual elevation & enlargement, of, elevation & enlargement of the land, an island must would be a far more fertile source, as far as we can judge, of new forms, than a continent. (A) ) (A)

(But if we look to the origin of a continent, every geologist will admit that have in most cases, they it will have first existed as separate islands, gradually increasing in size; & therefore all that which has been said concerning the probable changes of the forms tenanting a small archipelago, is applicable to a continent in its early state. Furthermore, a geologist, who reflects on the geological history of Europe, the only region well known, will admit, that it has been many times depressed, raised & left stationary. During the sinking of a continent, & the probable generally accompanying changes in climate, the effect on the species, ( except in their numerical proportions & [illeg] the extinction of some or many (from the lessening of rivers, subsidence of marshes, highlands becoming low [illeg]) would be small. until As soon as, however, the continent became divided into many isolated portions or islands, preventing free immigration from one part to another & with considerable changes of climate the effect on the species would be greater. But let the now island- broken continent, forming islands forming isolated islands, begin to rise, in[illeg] & new stations thus to be formed, exactly as in the

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first case of the upheaved volcanic islet; & we should shall have equally favourable conditions for the modification of old species, or forms, that is the formation of new races or species. Let the islands become reunited into a continent, & spe then the new & old forms, would each spread as far as the barriers [illeg] & the means of subsistence & the preoccupation of the land by other species would permit; some would perhaps becoming extinct. some few of the races would perhaps blend together, or others perhaps would, if they ever met. probably probably becoming extinct & some perhaps crossing & blending together. We should thus have a multitude mulitude of forms adapted to all kinds of slightly different stations, & diverse groups of antagonist or food-serving species. Being The oftener these oscillations of level had taken place, & therefore generally the older the land, the greater the number of species would tend to be formed. The inhabitants of a continent being thus derived in the first stage from the same original quarters parents; & subsequently from the inhabitants of one wide area; since broken up & reunited, all would be obviously related; & the inhabitants of the most different dissimilar stations on one the same continent would be more similar clos allied, than the inhabitants of two very similar stations on two of the main different divisions of the world.)

I need hardly point out, that we now can can obviously see why the number of species in one two districts, independently of the number of stations affordedby them, should be in some cases, as widely different as in New Zealand & the Cape of Good Hope. We can see knowing the difficulties in the transport of terrestrial mammals why islands, far from large main-lands do not possess them; we see the general reason, namely accidental transport though not the precise one,

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why certain islands should, & others should not, possess members of the class of Reptiles. We can see why an ancient channel of communication, between two distant points, as the Cordillera probably was between Southern Chile and the United States during the ice-period, and icebergs between the Falkland Islands & Tierra del Fuego, & gales, at a former or present time, between the Asiatic shores of the Pacific & its eastern islands, is connected with or we may now now say causes an affinity between the species, though distinct, in the two districts. even where all or the greater number are distinct. We can see why how the better chance of diffusion, from most of the d [illeg] divi several of the species of any genus having wide ranges in their own countries, explains the presence of other species of the same genus in other countries; & on the other hand of species with restricted powers of ranging, not g belonging to forming genera with restricted ranges. I may here remark. As everyone would be surprised, if two races of mankind reared in two different countries As everyone would be surprised if two exactly similar, but peculiar varieties of any species were rai reared raised by man, in two different countries, or at two very different periods so we ought not to expect in two countries, if when a form was undergoing changes, that the same an exactly similar form would could be produced, from the modification of an old one one in two distinct countries or at two distinct periods, where or when they would probably be exposed to somewhat different climates & almost certainly to different associates: Now ought we to expect: hence we can see why each species appears to have been produced singly in space & in time. I need hardly remark, that according

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to this theory of descent, there is no necessity of modification in a species when it reaches a new & isolated country; if it is able to survive & very widely diffused & in an isolated spot if it were well enough adapted to its new home to survive, & variation & selection did not seize on any slight variations are not selected better adapted to the new conditions, it would might retain, as far as we can see, its old form [illeg] so would it be in time. for an indefinite time. (A) Back of Page

This persistence of form would, however, probably be [illeg] be preserved happen be [illeg] comparatively seldom

preserved, through successive geological periods, or in widely distant & differently conditioned countries.)

Finally, as during the long periods of time & oscillations of level, necessary or probably so, for the formation of a continent, we may conclude, as above explained, that many forms would become extinct. & These extinct forms & those surviving or modifyed forms would necessarily either modifyed or not, will all be related together in each continent, in same manner & degree as as are the inhabitants of any two different sub- regions in that same continent. I do not mean to say that the present marsupials of Australia, or Edentata & Rodents of S. America have descended from any one of the few fossils of the same orders, which have been found discovered in these countries. It is possible that in a very few cases instances, this may be the case; but generally they must be considered as merely co-descendants of a common stocks. I believe this, from mere the improbable chance improbability,, considering the vast number of species which, as explained in the last Chapter, must by our theory have existed, that the comparatively very few fossils which have been found, should be the

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(A): As we see that some sub-varieties produced under domestication are more variable than others; perhaps some & some whole groups more than others; so in nature, perhaps, some species & genera are more variable than others, both either in certain countries or over the whole world. A close persistance The same precise forms, however of would, probabled probably be seldom preserved

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immediate & dis immediate & linear progenitors of those now existing. Recent as the fossils Mammifers of S. America are, who will pretend to say how that very many intermediate forms may not have existed. Moreover, we shall see in the ensuing Chapter, that the very existence of genera & species can be only explained, by only by a few species of each epoch leaving modified successors to a future period; & the more distant the future period, the fewer the progenitors at that first will be the linear heirs of that epoch. As by our theory all Mammmifers must have descended from the same parent stock, so is it necessary, that each continent land now possessing terrestrial Mammifers, shall at some time have been so far united to other land, as to permit the passage of Mammifers; & it accords with this necessity, that in looking far back into the earth's history, we find p[illeg]ss first great changes in the geographical distribution, & secondly a period, in Europe, where the mammiferous forms, most characteristic of two of the present main divisions of the world, were living together.

(I think then I am not justifyed in asserting, that the all or most of the above enumerated points, even to the & often trivial points in the geographical distribution of past & present organisms beings, (which points on must be viewed by the creationist as so many ultimate facts) follow as simple consequences of specific forms being mutable & being adapted by natural selection to

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diverse ends, conjoined with their powers of dispersal & the steady geologico-geographical changes, now in slow progress & that which undoubtedly have taken place. This large class of facts thus explained has far more than counterbalances many separate difficulties & apparent objections, weight in convincing my mind, of the truth of this theory of common descent.) than many separate difficulties [illeg] in disturbing, for one shaking the evidence.

(There is one observation of considerable importance may be here introduced, with regard to the improbability of many the chief transitional forms, between being found fossil between any two species, being found fossil. I formerly remarked With respect to the finer shades of transition being ascer discoverable, I formerly have before remarked, that no one has any cause to expect to trace them in a fossil state, without he be bold enough to imagine that geologists at future days epochs, will be able to trace from fossil bones the gradations between the Short-Horn, Herefordshire & Guernsey Alderney breeds of cattle. I have attempted to show, that rising islands, in process of formation, must be the best nurseries of new species specific forms; & these points are the least favourable for the embedment of fossils. I appeal to the state of the numerous scattered islands in the several great oceans: how rarely are do any sedimentary deposits occur on them; & where they present, they are mere narrow fringes of no great antiquity which the sea is generally removing wearing away, & destroying. The cause of this lies in isolated islands being generally volcanic & consequently rising points; & the effects of subterranean elevation is to bring up the surrounding

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newly-deposited strata within the wearing destroying action of the coast-waves: the strata, deposited at greater distances, & therefore in the depths of the ocean, will be almost barren of organic remains. These remarks may be generalized:— periods of subsidence will generally always be most favourable to an accumulation of great thincknesses of strata, & consequently to their long preservation; for without one stratum formation, be protected by successive ones strata, it will seldom be preserved from to a distant age, owing to the enormous amount of denudation, which seems to be the a general contingent of time;;— periods of e I may refer, as evidence of this remark to the vast amount of subsidence, evident in the great pile of Europæan formations, from the Silurian epoch to the end of the Secondary, & perhaps to even later. :— Periods of elevation on the other hand cannot be favourable to the accumulation of strata & their preservation to distant ages, from causes circumstance just explained alluded to, viz, of elevation tending bringing up the circum[illeg]t to bring to the surface the lately deposited circumlittoral strata (always abounding most in fossils) & destroying them. Tracts The bottom of tracts of deep water (little favourable even, however, to life) must be excepted from this unfavourable influence of elevation. In the quite open oceans, probably no sediment is accumulating, or probably at so slow a rate so slow, as not to preserve fossil remains, which will always be subject to disintegration. Caverns, shall no doubt, will be equally likely to preserve terrestrial fossils in periods of elevation & of subsidence; but, whether it be owing to the enormous amount of denudation, which

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all land seems to have undergone, no cavern with fossil bones, has been found older than the belonging to in the Secondary periods. Hence generally many more of marine fossil remains will be preserved to a distant age in any region of the world during periods of its subsidence, than of its elevation.

But during the subsidence of a tract of land, its inhabitants (as before shown) will, from the decrease of space , & of the diversity of its stations, and from the land being fully preoccupied by species with fitted to diversifyed ends means of subsistence, be little liable to modification from selection, although many may or rather must become extinct. With respect to its circum-marine inhabitants, although during the change from a continent to a great archipelago, the number of stations fitted for marine beings of this nature, this class, will be increased, their means of diffusion (an important check to change of form), will be greatly improved; for a continent stretching North & South, or a quite open space of ocean seems to be to them the only barrier. On the other hand during the elevation of a small archipelago & its conversion into a continent, we have whilst the number of stations are increasing, both for aquatic & terrestrial productions & spaces enlarging, in the land not and whilst these stations are not fully preoccupied by perfectly adapted species, the most favourable conditons for the production selection of new specific forms; but few of them will transitional organic beings, then living in their early transitional states Back of Page will be preserved (A)

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to a distant epoch; we must wait f during an enormous lapse of time, until long-continued subsidence shall have replaced taken the place of elevation in this quarter of the world for the best conditions of embedment & preservation of its inhabitants.

(A); we must wait, [illeg] to to a distant period; for we must wait for the embedment and preservation of after for an enormous lapse of time, for another great period of until long-continued subsidence, shall have take the place of elevation, for in this quarter, for for the best conditions of embedment & preservation of a numerous body of organic remains organic remains of the inhabitants in of that country or quarter of the world. of its inhabitants

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whereas Generally, the great pile mass of the strata in every part of the world, country, from having been chiefly accumulated during subsidence will be the tomb not of species either the transitional species, but of those either becoming extinct or remaining unmodifyed.)

 

The state of our knowledge & the slowness of the changes of land, do not permit us to test the truth of these remarks, by observing whether there are more 'fine' transitional or "fine" (as naturalists would term them) species, on a rising & enlarging tract of land or on an isolated island in process of formation, than on subsiding land. an area of subsidence. Nor do I know whether this is the case there are more 'fine' species on isolated volcanic islands in process of formation, than on a continent; but I may remark that at the Galapagos Archipelago the number of forms, which according to some naturalists consider sufficiently distinct to be considered as called naturalists are true species, & according to others naturalists consider as mere races, was is considerable: this particularly applies to the different species or races of the same genera, inhabiting the different islands of this archipelago. Furthermore it may be added (as bearing on the general facts discussed in this chapter) that when naturalists confine their attention to any one country, they have comparatively little difficulty in determining what what forms appear are permanent to call species & what to call varieties, that is forms, that is, those, which can be traced or shown to be probably to be descendants of some other forms; but the difficulty begins,

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& increase, as species are brought from many stations, countries & islands.It was this increasing, but I believe in few cases insuperable, difficulty, which seems chiefly have urged Lamarck to the conclusion that species are not immutable.)

Chapter III Chapter IV

On the nature of the affinities & classification of organic beings.

It has been observed from the earliest times, that organic beings fall into groups & these groups into others of several values, such as species into genera, & these into sub-families, into families, orders, &c. The number of the groups, from between the single species & the Kingdom to which it belongs, is arbitrary.. The same fact holds with those or beings, which no longer exist. as might have been expected from all fossil & recent organisms belonging to the same system. Groups of species seem to follow the same laws in their appearance & extinction, as do the individuals of any one species: do. we have reason to believe that first a few species appear, that their numbers increase, & that, when tending to extinction, first one the number of species decrease, till finally the group becomes extinct, in the same way as the a species becomes extinct, by the individuals becoming rarer & rarer. Moreover, groups like the individuals of a species appear to become extinct at different times, in different countries: the Palæotherium, was extinct much sooner in Europe, than in India.— the Trigonia was extinct in early ages in Europe, but now lives in the seas

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of Australia. As it happens that one species of a family has will endure or retain its present form, for a much longer period than another species; so we find that some whole groups, such as the marine mollusca, tend to retain their forms or to remain persistent for longer periods, than other groups, for instance than the terrestrial mollusc mammiferous mammalia.— Groups, therefore, in their appearance, extinction, & rate of change or succession, seem to follow nearly the same laws with individuals of a species.

The proper arrangement of the species into groups, according to the Natural System is the object of all naturalists; but scarcely two naturalists will give the same answer to what is the Natural System, & how are we to recognize it. The most important characters, it might be thought (as it was by the earliest classifyers) ought to be drawn from those parts of the structure, which determine its habits & place in the œconomy of nature, which we may call the final end of its existence. But nothing is further from the truth than this; how much external resemblance there is between the or little Otter (Chironestes) of Braz Guiana, & the common Otter, or again between the common swallow & the swift; & who can doubt that the means & ends of their existence are closely similar; yet how gross grossly wrong would be that classification, which included [illeg] in the first case put near close to & each other a marsupial & placental animal & two birds with widely different skeletons. & Relations

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, such as t[illeg] in these two cases, or as that between the Whale & fishes, are are is denominated, as "analogical" or are sometimes described as "adaptive characters". They are infinitely numerous & often very singular; but are of no use in the classification of the higher groups. How it comes, that in the idea of individual creations, that those certain parts of the structure, by which the habits & place of the species are settled, although are of no use in classification, whilst other parts, formed at the same time with other parts are of the greatest, it would be difficult to say on the theory of separate creations.) ⁋

(It has been supposed that by some naturalists (Lamarck, Whewell &c) that according to the relative physiological importance of the organs to life, their greater or less resemblance in two forms, should serve as the basis of the Natural System; that is the a less degree of resemblance of in an important organs important to life ought indicates a closer affinity, than does a greater resemblance in unimportant organs. There is some truth in this, but as a general proposition it seems to be false (A)

For it is universally admitted that the same part or organ, which is of the highest service in classification in one group, is of very little in another, though in both cases, as far as we can see, of equal physiological importance: Moreover, such characters, quite unimportant physiologically, such as whether the covering of the body consists of hair or feathers, or the existence [illeg] [illeg] whether the nostrils communicate with the mouth &c &c are of the highest generality in classification: even colour, which is in so inconstant in many species, [words illeg] will sometimes well characterize even a whole group of species.— Lastly the fact that no one character is of such so much importance in determining to what great groups an organism belongs, as the forms through which it the embryo passes in from the germ upwards to maturity, cannot be reconciled, with the physiolo idea, that classification, follows

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difficult to say, on the theory of separate creations.) ⁋.

(Some authors, as Lamarck, Whewell &c, believe that the degree of affinity on the Natural System, depends on the degrees of resemblance in organs, more or less physiologically important for the preservation of life. The scale of importance of organs to the preservation of life is admitted to be of difficult discovery. As But quite independent of this, the proposition, as a general rule, though partially true, must be rejected as false, though it may be partially true.

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: thus (B) in our most families of plants, the æstivation, the manner in which the petals &c are folded over each other, is found to be a afford an unvarying character of high importance in most families of plants;, & a accordingly any difference in this respect would be sufficient to cause a species to the rejection of a species from many families; but in the Rubiaceæ the æstivation is a varying character, & a Botantist would not lay much stress on it, in deciding whether or not to put a class a new species in this family.

(A)

We can only thus understand Linæus' well-known saying that the genus characters do not make genus; but that the genus gives the characters: a classification, independent of characters, is here presupposed.

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according to the greater degrees of resemblance in the organs parts of most physiological importance. The affinty of the common rock Barnacles' affinity with the Crustacea, can hardly be perceived in more than a simple character in its mature state, but whilst young, locomotive, & furnished with eyes, its position affinity cannot be mistaken. The cause of the greater value of characters, drawn from the early stages of life, can, as we shall in a succeeding chapter see, be in some degree explained, in a considerable degree explained, on the theory of descent, althougn inexplicable on the the views of the Creationist.)

(Practically naturalists seem to classify organic beings according to the resemblance of those parts or organs, which in related groups seem to are not uniform or vary least. (B)

But this rule is obviously is so arbitrary a formula, that most naturalists seem to to seek be convinced that something further by the ulterior is represented by the Natural System; they always seem appear to consider think that the aggregate similarity of parts of characters a structure does not actually make the Natural System, but that it is only by such similarity, we can discover this Natural System. (A)

Hence many Naturalists have said that the Natural System reveals the plan of the Creator; but to me, without it be specifyed whether order in time or place or what else is meant by the plan of the Creator; such expressions appear to me to leave the question exactly where it was.)

(Some Naturalists consider that the geographical position of a species may enter into the consideration of the group into which it should be placed; & most

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Naturalists (either tacitly or openly) give value to the different groups, not solely by their relative differences in structure, but by the number of forms thus included in them. Thus a genus containing a few species, might be & has often been, raised in to a family on the discovery of several other species. Many natural families are retained, although most closely related to other families, from including a great body number of closely similar species. The more logical naturalists, would perhaps, if he could, reject these two [illeg] contingents in classification. As a result from the From these circumstances & especially from the undefined objects & criterias of the Natural System, the number of divisions, such as genera, subfamilies, families &c&c is has been quite arbitrary; undefined; [words illeg] in [illeg] as the physiological importance (of [illeg] of [illeg] organ does not determine its value in classification; it must be most difficult to know judge; without the clearest definition, it can be hardly possible to decide whether two groups of forms species, are of equal value & of what value? [illeg] whether they they should be both be called two genera or two families; or whether one should be a genus, & one the other a family?

(I have only one other remark on the affinities of organic beings; that is when two quite distinct groups approach each other, the approach is generally generic & not specific special; I can explain this, most easily by an example; of all Rodents, the Bizcacha, by certain peculiarities in its reproductive system, approaches nearest to the Marsupials; of all Marsupials, the Phascolomys on the other hand, appears to approach in the form of its teeth & intestines, approaches nearest

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to the rodents; but there is no especial specific espe special relation between these Bizcacha & Phascolomys. two genera, the Bizcacha is no nearer related to the Phascolomys than to any other Marsupial, in the points in which it approaches this division; nor again in the Phascolomys, in the points of structure in which it approaches the rodents, any nearer related to the Bizcacha, than to any other

Rodent;— Other examples might have been given, chosen chosen, but I have given (from Waterhouse) this example, as it illustrates another point, namely the difficulty of determining what are anological or adaptive & what real affinities:— nor is this difficulty wonderful for it seems that the teeth of the Phascolomys though appearing closely to resemble those of a Rodent are found to be built on the Marsupial type, & it is thought that these teeth & consequently the intestines may have been adapted to the peculiar life of this animal, & therefore may not show any real relation. The peculiarity structure in the Bizcacha, consisting of a t[illeg] which that connects it with the Marsupalia, does not seem a peculiarity related to its means manner of life, & I no imagine one no one would doubts shows is that this shows a real affinity between the Rodent & the Marsupalia, though not more with any one Marsupial species, than with another.— The difficulty of determining what relations are real & what analogical, is far from surprising, when no one pretends to define the meaning of the term, relation or the in what the [2 words illeg] consists on them, or to define the ulterior object of all classification. We shall immediately see, on the theory of common descent, how it comes that there should be real & analogical affinities; & why the former alone should be of value in the formation of the higher groups; classification,— — difficulties which it would be hard I believe, impossible to explain on the ordinary theory of separate creations.)

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Let us now for a few minutes turn to the classification of the generally acknowledged varieties & sub-varieties of our domestic organic beings; we shall find them grouped systematically arranged in groups of higher & higher order value:; DeCandoelle has treated the varieties of the Cabbage exactly as he would have done a natural family with various divisions & sub divisions: these In dogs again, we have one main division, which may be called the Family of [illeg] hounds; of these there are several, we will call these, genera kinds, such as Blood-Hounds, Fox hounds, & Harriers, & of each there again we have different kinds species, as the blood hound of Cuba & that of England, & of the latter [illeg] again, kind breeds, truly producing [illeg] sub-varieties of the latter their character own kind, which must may be considered as subvarieties called races or varieties. Here we see a the classification, really used, & practically used, which typifies on a lesser scale that of the the higher divisions groups which holds good then in nature. & practically used as in groups of higher value In the natural system, & amongst domestic races the number of forms much influences the [illeg] number of [illeg] divisions or groups of hi instituted between those most alike & those least alike, seems to be quite arbitrary. The number of the species or varieties forms in both cases seems practically to influence the formation denomination of groups to receiving them. In both geographical distribution has sometimes been used as an aid; to classification; amongst varieties, I may instance those the cattle of India or the sheep of Siberia, which possessing some characters in common, cannot then permit a classification of Indian & Europæan cattle or Siberian & Europæan sheep.— Amongst domestic varieties we have even something very like the relations of "analogy" or "adaptation";

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(A) and are used for the same purposes

& they fill nearly the same end in the oeconomy of the farmyard; but although the swede so much more resembles a trunip there its presumed parent the Field Cabbage, no one thinks of putting it out of the cabbbages into the Turnips.—

(B.) Lastly varieties often become extinct; sometimes from unexplained causes, sometimes from accident, but more often from the production of more useful varieties, & the less useful ones being destroyed or bred out.)

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Common Turnip & Sweedish turnip are are both artificial varieties which strikingly resemble each other (A) Back of Page though descended from different parents & in every book treating on varieties widely separated [illeg] : thus the Greyhound & Racehorse, both having been selected & trained for extreme Fleetness for short distances, present an analogical resemblance of the same kind, but less striking, as that between the Little Otter (Marsupial) of Guyana, & the Common Otter,— though these two animals otters are really less related than is the horse & dog. We are even cautioned by authors treating on varieties to follow the Natural in contradistinction of the a artificial System, & not, for instance, to class two varieties of the Pine-Apple [illeg] near each other, because their fruits accidentally resemble each other closely (though what the fruit may be called the the final end of this cultivated hot-house plant) plant in the œconomy of its world, the hot-house) but to judge from the general resemblance of the entire plants. (B)

(I think it cannot be doubted that the main cause of all the varieties of the which have descended from the aboriginal dog or dogs, or from the aboriginal wild cabbage, not being equally unlike, but on the contrary obviously falling into groups & sub-groups; must in chief part be attributed to different degrees of true affinity relationship;,— for instance, that the different kinds of blood-hounds have descended from one stock, whilst the harriers have descended from another stock, but that both these have descended from a different stock from that which has been the parent of the several kinds of grey-hounds. In some few cases, we absolutely know that this has been the case We often hear of a Florist having some

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choice variety & breeding from it, & thus getting a whole group of sub-varieties more or less characterized by the peculiarities of the parent. The case of the Peach & Nectarine with their many varieties might have been instanced. No doubt that the relationship of our different domestic breeds has been obscured in an extreme degree by their crossing; & from the slight difference between many breeds, it might sometimes has often probably often happened that a "Sport" from one breed would more has less closely resembled its parent breed, it than the some other breed, than it our parent breed, & has therefore has been classed amongst with with the former. latter. (A)

Notwithstanding these great sources of doubt difficulty, I apprehend if it were possible, everyone would admit that if it were possible a geneological classification of our domestic varieties, would be the most satisfactory one; & as far as varieties were concerned, would be the Natural System. In attempting to follow out this object, a person would have to class a variety whose he would when he did not know the parentage of a variety, have to examine & compare he did not know, by its external characters,

its class it, by its cha quite useless resemblance with others, whose position were ascertained; & but in doing this he would have the ulterior object, of its descent in view, in the same manner the every regular systematist seems to have some ulterior object, which he calls the plan of the creation.

, but he would have a distinct ulterior object in view, namely its descent, in the same manner, as a regular systematist seems also to have some an an ulterior but undefined object end in all his classifications. Like the regular systematist, he would

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Moreover,  the effects of a similar climate might may in some cases have more than counterbalanced the similarity consequent on a common descent; though I should think the similarity of the breeds of cattle of India or sheep of Siberia, was far more probably due to the community of their descent, than to the similarity of the effects of climate of on animals derived descended from different stocks.) ⁋.

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No doubt, as a  general frequent rule, the more important the organ, as being less related to external influences, the less liable it is to variation;

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not care whether his characters were drawn from more or less important or unimportant organs, as long as he found in the tribe in which he was examining, that the characters from such parts were persistent; thus amongst pigs cattle, he would does value a character drawn from the form of the ear horns, as much as from the metamorphosed feet of the _____ Breed, if he found the form persistent amongst pigs, more than from the proportions of the limbs & whole body, for he finds that the shape of the horns is persistent amongst cattle whilst the bones of the feet varied. limbs & body vary. (A) He : but he would expect that according to the object, for which the races had been selected, parts more or less important would might differ; so that the most characters drawn from parts, generally most liable to vary, as colour might in some instances be more highly serviceable; as is the case.— He would admit that general resemblances, scarcely definable by language, might sometimes serve to allocate a species by by its nearest congener. He would be able to assign a clear reason, why the close similarity of the fruit in certain two varieties of the pineapple, & in the so-called root in the Common & Sweedish turnips, & & why the similar gracefulness of form in the grey-hound & racehorse, should not are characters of little any value in for in classification; namely because they are the result not of community of descent, but either of selection for a common end,, or of the analogical results effects of climatic influences similar external conditions.).)

(Thus seeing that both classifyer of species & of varieties, are obliged to follow works by the same means, to make similar distinctions in the value of the characters & meets with similar difficulties  & that both one have one appe[illeg] or a ought to have [illeg] the other would (if he could) & the other would have if he could have an ulterior object in their classification; I cannot doubt that the same cause, and that the classification of species seems to have some ulterior but ill defined object in view, and the classifying of varieties, as far as lies in his power, which makes has made amongst

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and that both seem to have in their classification, an ulterior object in view; I cannot avoid simply suspecting that the same cause, which has made amongst

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not care whether his characters were drawn from more or less important or unimportant organs, as long as he found in the tribe in which he was examining, that the characters from such parts were persistent; thus amongst pigs cattle, he would does value a character drawn from the form of the ear horns, as much as from the metamorphosed feet of the Breed, if he found the form persistent amongst pigs, more than from the proportions of the limbs & whole body, for he finds that the shape of the horns is persistent amongst cattle whilst the bones of the feet varied. limbs & body vary. (A)

He : but he would expect that according to the object, for which the races had been selected, parts more or less important would might differ; so that the most characters drawn from parts, generally most liable to vary, as colour might in some instances be more highly serviceable; as is the case.— He would admit that general resemblances, scarcely definable by language, might sometimes serve to allocate a species by by its nearest congener. He would be able to assign a clear reason, why the close similarity of the fruit in certain two varieties of the pineapple, & in the so-called root in the Common & Sweedish turnips, & & why the similar gracefulness of form in the grey-hound & racehorse, should not are characters of little any value in for in classification; namely because they are the result not of community of descent, but either of selection for a common end,, or of the analogical results effects of climatic influences similar external conditions.).)

 

(Thus seeing that both classifyer of species & of varieties, are obliged to follow works by the same means, to make similar distinctions in the value of the characters & meets with similar difficulties

[pinned insert:] and that both seem to have in their classification, an ulterior object in view; I cannot avoid simply suspecting that the same cause, which has made amongst

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our domestic varieties, groups more or less related, of higher & higher value & sub-groups, has has made similar groups, (but of higher values) amongst bot the species past [illeg] & now existing species; & that this cause, is the community greater or less propinquity of actual descent. in the now related The simple fact of every species, both those long since extinct & those now living, being, grouped as well like as [illeg] our domestic varieties, as well as [illeg] domestic varieties like ones acknowledged divided into groups of related in resembling others in the first or greatest degree, & groups of others in a second degree, & again others in a third degree in, being divisible into genera, families, orders;— divisions analagous, to those into which varieties are divisible, is otherwise an inexplicable fact, & only not remarkable for its familiarity.)⁋

(But f[illeg] if we admit that all the species of a genera (like the varieties of a species,) have descended at some remote epoch from one commom form stock many some other facts [words illeg], can be likewise explained.

(Let us suppose for explification that, a species become spreads & arrives at six into six or more different regions, or being already diffused over one region area, let this region area be divided into six distinct regions, exposed to different conditions & with stations slightly different, into so that to occupy which, the six slight & not [illeg] fully occupied, (A) so that six different races might be selected, so that six different races or species are formed by selection, each best fitted to its new country habits & station (A)

We The races or new species supposed to be thus formed would be closely related to each other, & would either form a new genus or subgenus or would rank probably forming a slightly different section in the genus to which the parent species belonged. In the course of ages, let this

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The advantage

One region being in such degree exposed to same physical condition As In the same great region the organic beings are some degree allied & physical condition often like, we might expect that if one division, the old species from having some advantage over antagonist species becoame modified, it wd be so in the other districts.

As in the same great region the inhabitants are in some degree allied, & the physical conditions often in some respects alike, we might expect, that if our species, from having some advantage over antagonist species, became modifyed in one of the six districts, it would be apt to become modifyed in some or all the other districts: hence its spreading hence six different races

there is no improbability, of our if several new races or species being found, if, one is found in any one of the district; the mere diffusion spreading or existing diffusion, of one parent &c show that the species without modification is well able to hold its own against antagonist forms.

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for variation.)

(Moreover, as the same advantages over antagonist species which caused one species to be preserved & modified into others several offspring species, would give to their offspring species in their turn a better chance of being preserved under new & modified forms, & modified into new forms; so that it would result that the new & increasing species were allied in every country, which necessarily would occupy the place of individuals of other species, would be related as, from the strong tendency of every all characters to be inherited, most of the new species gradually & successively forming in any country, would generally be descended from the same stocks; so it is probable, that the inferiority, whatever it may have been, which allowed the new form to occupy the place of the old ones, would be common to old species of the same stocks, so would it happen that as the new species were related together,, the old ones which in consequence were becoming rarer & rarer & extinct, would also be related. Hence whole genera, like the individuals of a species, would by the gradual, successive, & local losses of spe different species, become extinct; and whole families would become extinctby from the successive & local of losses of the allied genera. There might, & of course then would be occasional exceptions. From what has gone before we can also see, that genera would appear on the face of the earth, by the slow & successive appearance of new species; & families by the slow formation production (with the extinction of some species) of new genera that is descendants from some of those species the several forms. with the Now as far as our knowledge serves, it is in this remarkable manner that groups of species appear on

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140b

(A) I may remark that in any case it is probable that if a species becomes modifyed in any one sub-region, it is probable that it will become modifyed in some other of the sub--regions over which it is diffused. For its modification, shows that its organization is in some degree plastic, so as shown to be capable of being rendered plastic; its diffusion proves that it is able to struggle with the other inhabitants of the several sub-regions; and as the organic beings of every great region are in some degree allied & as even the physical conditions are often in some respects alike, we might expect that a modification in structure, which gave it our species some advantage over antagonist species in one sub-region, would be followed by other modifications in other of the sub-regions.

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& during the consequent contingent physical changes, it is probable that some of the six new species would be destroyed; but the same advantage over other antagonist species, whatever it may have been, (whether more tendency to vary, or some peculiarity of organization structure, powers of mind, or even means of distribution constitutional [illeg]ig[illeg]) would tend which allowed preserved the parent species & allowed which in the parent-species & in its six selected & changed species-offspring, which preserved caused allowed them against to prevail over antagonist other antagonist species, would generally tend tend to preserve some or many of them through a long period. If then two or three of the six species were thus preserved, they in their turn would during continued changes give rise to so as many small groups of species: if their those two or three two their new the parent-species of these small groups [illeg] closely similar, these new species-offspring would form one greater genus, barely perhaps divided divisible into two or three sections: but if the new parent species were considerably unlike, their selected & altered species-offspring would, from inheriting most of the peculiarities of their two different parent-stocks, form either two or three more sub-genera or (if the course of selection tended in different ways) genera. Species again descending from two of these genera And lastly species descending from some of the different species of the new new first genera would might would form new genera; & such genera collectively might would form a natural

family.)⁋

Hence it results from varieties or races inheriting most of the qualities

⁋(As must follow from the simple fact, of a variety being

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selected & modifyed that it possesses & acquires some advantage over the other species in the same districts; & as all such advantages would tend to be transmitted by the [illeg] heredetary tendency tend to be inheritable there must be always a geometrical tendency in every [illeg] species, which undergoes modification, to transmitt to be the parent of more that one new groups of species, & again of from each of these to be the parent of new groups, & so geometrically onwards. The result of this would be, if there was no counteracting agency [illeg] viz extinction, an infinitely increasing number of groups; & further there would be a tendency from the struggle of each species to make geometrically increasing groups. that from any one period, only a few species would transmit new species-offspring to an immensely remote epoch

that in each great class all the organic beings species in each great class existing at any period would be the descendants of a fewer forms, & fewer parent-forms, the further we looked backwards; & consequently at this any one period all the existing

species in each great class would bedistantly related fall into as we see they are; & the number of species in each groups to which they belong, would continue to increase in a few great groups subdivisions, in the manner in which we see that they are. that the number of the groups If there was no counteracting agency, Another result would be, that the number of groups would go geometrically increasing; but we have no reason to suppose that this has been the case taken place, & we know that there is counteracting agency in extinction, & that as occasionally a species could be be exposed to the conditions favourable for variation favourable for variation, or the production of a new form. so far from there being any necessity for every species leaving a modified descendant, we may feel pretty sure, from the [illeg] that only occasionally a species can become exposed to the conditions favourable

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The extermination of species will follow from the in increase of other species, especially changes in the external conditions,— from the increase or [illeg] immigration of more favoured forms or their modification: and as allied many of the species, that is species of the same genus form partaking many characters in common will generally be which are undergoing modification in that in any one great region (& indeed over the world) will very often be allied ones from partaking of com many common characters & therefore advantages in common; so the species, whose place the new or more favoured ones are seizing, from partaking of a common inferiority, (whether in any particular point of structure or general prowess of mind, distribution, capacity of variation &c &c) will apt to be allied. Consequently species of the same genus will first tend slowly & one after the other to become successively rarer & rarer in numbers, & finally extinct; & as each last species of several allied genera becomes extinct fails, the family even will become extinct. There may of course be occasional exceptions to the entire destruction of genera any genus or family. From what has gone before, we have seen, that

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in the

& blow from the

of subsided land, indicated by a certain class of coral-reefs, may have helped the migration of species; but here again, it is not obvious why the migration of one species in certain directions should have carried other allied species, without we suppose that each species with an Indio-asiatic

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143b

this slow & successive formation of new species from the same stock will produce make a new genus, & that the slow & successive formation of new groups other new species from an allied stock will make another genus; & such genera will make a new family. Now, as far as our knowledge serves, it is in this remarkable slow & gradual manner, that groups of species appear on & disappear from the face of the earth.)

[176v-177v]

(142, & 143a)

The extermination of species will follow from the in increase of other species, especially changes in the external conditions,— from the increase or [illeg] immigration of more favoured forms or their modification: and as allied many of the species, that is species of the same genus form partaking many characters in common will generally be which are undergoing modification in that in any one great region (& indeed over the world) will very often be allied ones from partaking of com many common characters & therefore advantages in common; so the species, whose place the new or more favoured ones are seizing, from partaking of a common inferiority, (whether in any particular point of structure or general prowess of mind, distribution, capacity of variation &c &c) will apt to be allied. Consequently species of the same genus will first tend slowly & one after the other to become successively rarer & rarer in numbers, & finally extinct; & as each last species of several allied genera becomes extinct fails, the family even will become extinct. There may of course be occasional exceptions to the entire destruction of genera any genus or family. From what has gone before, we have seen, that

[pinned insert:] this slow & successive formation of new species from the same stock will produce make a new genus, & that the slow & successive formation of new groups other new species from an allied stock will make another genus; & such genera will make a new family. Now, as far as our knowledge serves, it is in this remarkable slow & gradual manner, that groups of species appear on & disappear from the face of the earth.)

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& disappear from the face of the earth.) in this remarkable manner;—

(The manner, in which according to our theory the arrangement of species in groups is due to partial extinctions,

(The origin of genera & other groups, according to this theory of descent, will perhaps be rendered clearer in another the following way. Let us by suppose [illeg] in any one great class; for instance in the Vertebrata, that every species which had existed during all ages, should send & every variety of every age during each successive age, had sent down one unaltered descendant whether (either fossil or living) to the present time; we should then have had one enormous series, including by small gradations every existing known form of the Vertebrata; consequently the existence of groups or chasms in the series, in some parts of greater width & in some of less, of [illeg] value is solely due to changes in the series, formed by old species & groups of species not having former species & whole groups of species not having thus sent down descendants to the present time.)⁋.

The series of organisms in any one class, may be compared to the descendants of a man, who lived a several centuries ago; they would be if every child

(With respect to the 'analogical' or 'adaptive' resemblances between organic beings, which are not really related; already often referred

to; I will only add that probably the isolation of different groups of species is probably an important element in their formation: thus we can easily see that in a large increasing island, or even continent like Australia stocked with only certain orders of the main classes, that the conditions would be highly favourable for species from these orders would to become adapted to play a parts in the œconomy of nature,

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which in other countries was played performed by a tribe especially adapted to it such ends..— We can understand how it might happen that an otter-like animal in Australia, or S. America if at anytime peopled only by marsupials, might have beeen formed by slow selection from the more carnivorous marsupial types; Much has been written about the groups  Much has been written about the groups, in each class consisting of corresponding in number, which is now generally disbelieved; I refer to it, only to observe, that most of the great divisions of nature having species adapted land, air, water: thus we can understand that curious case in the southern hemisphere, where there are no Awks,, but many petrels, of a Petrel having been modified into the external general form & to play the same office in nature, with the Awks of the northern hemisphere; although the habits & forms of the Petrels & Awks are normally so wholly different.

Finally It follows from this our theory, that two orders must have descended from the same one common stock at an immensely remote period epoch; & we can perceive, why when a group of species in either order, or in both, shows some affinity to the the a species other order, why the usually affinity is usually generic & not specific;— particular;— that is, why the Bizcacha amongst Rodents, in the points in which it is related to the Marsupial, is related to the whole group, & not particularly to the Phascolomys, which of all Marsupialia is related most to the Rodents. For the

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Bizcacha is related to the present Marsupialia, only from being related to their common parent stock; as the Phascolomys is related to the parent-stock of the Rodents. And generally as an extension of this remark it will may be found, where we find observed in the writings of most naturalists, that when an organism is described as intermediate between [illeg] two great groups, its relations are not we do not observe that their affinities [illeg] described [illeg] do that these affinities as [illeg] are not to particular species of each either group, but to each both groups, as a wholes. ) & the (A)

(Finally then we see that all the leading facts in the affinities & classification of organic beings, can be explained on the theory of descent the Natural System, being simply a geneological one. The similarity of the principles of grouping in classification, between varieties & in the species both living & extinct is at once explained; follows; [illeg] the rules followed & difficulties met with bein being the same. The existence of genera, The existence of genera, families, orders, &c, & their mutual relations, (B)

are explained. These terms of affininty, relations, families, adaptive characters, &c, which naturalists cannot avoid using though though metaphorically, cease being so, & are full full of plain [illeg] signification.)

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: a little reflection will show how exceptions (as that of Lepidosiren, a Fish, closely [illeg] related both to Reptiles but connecting certain Fish & Reptiles & Fish) might happen, from a a few descendants, in both orders, of this, little or not at all modifyed, having [illeg] from the common parent-stock. of the early forms species, originally closely connected the two orders, which at an early epoch branched from the common parent-stock of the two orders having survived little or not all at modifyed in nearly their original state, to the present time

(A)

A little reflection will show how exceptions (as that of the Lepidosiren, a fish more closely related to certain particular reptiles) might occur, namely from a few descendants of those species, which at a very early period branched out from the common parent-stock of the two orders or groups, having survived in nearly their original state, to the present time.)⁋.

(B) naturally ensues, from extinction going on at all periods amongst the diverging descendants of a common stock.

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occasionally (A) some of the bones are merely represented by an apparently useless smooth style, or are closely soldered to the other bones; but the unity is not by this destroyed & hardly rendered less clear.

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Chapter V.

Unity of type in the same same

Great Classes, & morphological structures.

Scarcely anything is more wonderful or has been oftener insisted on, than, that the organic beings in each great class, though living in the most distant climes & at im periods immensely remote, though fitted to widely different ends in the œconomy of nature, yet that all in their internal structure an wond evince an obvious uniformity. What, for instance, is more wonderful than that the hand to clasp, the foot or hoof to walk, the Bat's wing to fly, the porpoises fin to swim, should all be built on the same plan, & that the bones of which in their position & number are should be so similar, that they are can all called be classed & called by the same names. (A)

We see in this fact some deep bond of union between the organic beings of the same great classes,— to illustrate which is the object & foundation of the Natural System. The perception of this bond, I may add, is the evident cause that Naturalists make an un illdefined distinction between true & adaptive affinities.)

There is another allied or rather almost identical class of facts, included in the admitted by the least visionary naturalists & denominat included under the name of Morphology. These facts show that in an individual organic being, sever all or several of its organs consist of some other organ metamorphosed: thus the sepals petals, stamens pistils &c of every plant

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can be shown to be metmorphosed leaves & thus not only the number, & positions, & transitional states of their several organs, but likewise their gradual becomi monstrous changes, can be most lucidly explained. It is believed that the same laws hold good with the gemmiferous vesicles of zoophytes. In the same manner the extra number & position [illeg] of the extaordinarily complicated jaws & palpi of crustaceans & insects, & likewise their differences in the different groups, all become simple, on the view of their parts being metamorphosed legs. The skulls again of the Vertebrata are composed of three metamorphosed vertebræ, & thus we can see a meaning in the number & strange complications of the bony case of the brains. In this latter case & in that of the jaws of the Articula Crustacea, it is only necessary to see a series, taken from different divisions in each class, to admit the truth of these views. It is evident that when in each species of a group, their its organs consist of some other part metamorphosed, that there must also be a "unity of type" in such a group. And in such cases, as that above given, where in which the foot, hand, wing, & paddle are said to be given in the last paragraph, where it is usually only said that the parts or organs of the species of a group are constructed on a uniform type; if we could trace perceive in such parts or organs, we could traces of some other those metamorphosis of other part having been signs traces of an apparent change from some other use or function;

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metamorphosed, we should say that strictly include such parts or organs in the department of morphology: thus if we we it could trace in the limbs of the Vertebrata, as we can in their ribs, traces of their our apparent existence change from being processes of the vertebræ, we sh it would be said that in each species the limbs were "metamorphosed spinal processes" & that in all the species, throughout the class, the limbs displayed a "unity of type".) be shown that in the Vertebrata each extremity was one or more vertebræ metamorphosed (as in the skull) we should say that these in each species were both "metamorphosed parts"; [illeg] were [illeg] that they displayed in the whole throughout the group a "unity of type".)

(These wonderful facts of the hoof, foot, hand, wing, paddle, of animals both in living & extinct animals, being all constructed on the same framework, — and again of the petals, stamina, & germens &c being metamorphosed leaves, can by the Creationist be viewed only as ultimate facts, & incapable of explanation. Whilst on the our theory of descent, these facts all necessarily follow; for by this theory all the beings of any one group class,, say of the mammalia, are supposed to be descended from one parent-stock & to have been altered by such slight steps, as man effects by the selection of chance variations. Now we can see, that possibly according to this view, that a foot might be selected with wider longer & longer bones, & wider connecting membrane, till it became a swimming organ, & so on till it became an organ to glide through the air or by which to flap along the surface, or to glide through the air over it, & fro lastly to fly through the air: but in such changes

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there would be no tendency to alter the framework of the internal inherited structure. Parts might become lost (as in the tail in dogs, or horns in cattle, or the pistil in plants), others might become united together, (as in the feet of the Lincolnshire si breed of pigs & many garden flowers); similar parts might become increased in number (as the vertebræ in the tails of pigs &c &c, & the fingers & toes in six fingered races of men & in the Dorking Fowls), but such changes would not are admitted by Naturalists not to destroy the uniformity of type analagous variations of this kind take place in nature, & are not considered by Naturalists to destroy the uniformity of the types. We can, however, conceive such changes to be carried to such lengths, that the unity of type might be obscured & finally be undistinguishable; & the case paddle of the Plesiosaurus has been advanced, as an instance in which parts of some which, Reptiles the uniformity of type can hardly be recognized. I need hardly add that If in such after long & gradual changes, some common some in any part of an organism, the structure of the descendants from any parent-stock, evidence (whet either from monstrosities changes, or a or forms a graduated series) could be still percieved in the parts in question, detected of the part or function, it which certain parts or organs played in the parent-stock, before these changes, these parts or organs might be strictly called denominated, by their former function, with the epithet term "metamorphosed" appended. Naturalists when have used this term, in the same manner as they have been obliged to use the terms of affinity & relation, metaphorically; & without [illeg] a [illeg] when they affirm, for instance that

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the jaws of a Crab are metamorphosed legs, they are far from meaning meaning that the jaws either during the life of the individual Crab, or of its progenitors, were really legs. By our theory this term asssumes its literal meaning; & this wonderful fact of the complex jaws of an animal, retaining numerous characters, which they would ha might well would probably have retained, if they had strongly really been changed metamorphosed during many successive generations from real true legs, is simply explained.)

The unity of type in the great classes is shown in another & very striking manner, namely in the similar stages through which the embryo passes in coming to maturity. Thus, for instance, at one period in of the embr embryo, the wing of the bat, the hand, hoof, or foot of the quadruped & the fin of the porpoise, do not differ, but consist of a simple, undivided bone. At a still earlier period the embryo of the fish, Bird, Reptile & Mammal all strikingly resemble each other. Let it not be supposed that this resemblance is only external; for on dissection the arteries are found to branch out & run in a peculiar course, wholly unlike the cours in the full grown mammal & Bird, but much less unlike that in the full-grown fish; for they run as if are to aërate blood by branchiæ branchiæ on the neck, & traces of of which, even the slit-like orifices of these branchiæ can it can be discerned. How wonderful is this fact; especially when we reflect that similarity in the arteries of fact, in animals, about to be developed into such different

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forms, & two great classes of which respire only in the air: moreover as the embryo of the mammal is matured in the parent body, & of the bird in an egg in the air, & of the Fish in an egg in the water, we cannot hardly believe that this course of the arteries is related to any external conditions. In all shell-fish also, (Gasteropods) the embryo passes through the the same simple a state, analogous to that of the Pteropodous Mollusca: in amongst where insects again, even the most different ones, as the moth, fly & beetle, the crawling larvæ of whole great orders are closely analogous: are then analogous. of a the simpler articulate animals: in amongst: in the Radiata, jelly-fish, the in its embryonic state, resembles a polyps, & in a still earlier state an infusorial animolecule;— as does likewise the young embryo of the Polyps. The greater resemblance of the embryo in [illeg] of the Mammal to a Fish & of the larvæ of insects to some of the simpler articulata of groups; & of the jelly-fish to a polyps The From the fact of the embryo of a Mammal at one period more resembling a Fish more than its parent parent future form; and of from the larvæ of in several of all orders of insects more resembling thos the simpler Articulate orders animals, than their parents future forms parent insects; and from such other cases, as the embryo of the jelly-fish being resembling a polyps much nearer than its future a perfect jelly-fish; it has often been asserted that the higher animal, in each class, passes through the state of a lower animal, for instance that the Mammal amongst the vertebrata passes through the state of a lower animals a Fish; but Müller denies this, & affirms that the young Mammal is at no time a Fish, as does Owen assert that the embryonic jelly fish, is at no time a polyps, but that Mammal & fish, jelly-fish & polyps pass through the same state; the Mammal & Jelly-fish

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only being further developed or changed.)

(As Although the embryo, in most cases, is possesses a less complicated organisation structure, than that into which it is to be developed; & hence is it might have been thought that the resemblance of the embryo to less complicated forms of in the same great class, embryonic state, & its analogies with less developed orders or classes of the division to which it belonged, was in some manner a necessary preparation for its this higher development; but in fact the embryo during its growth may become either simpler or less as well as more complicated. Thus in certain female Epizoic Crustaceans, which in their mature state consist of a mere sack, containing a great large body simple digestive & generative apparatus, are without have neither eyes or any organs of locomotion; and they consisting consist of a mere sack with an a simple apparatus for digestion & procreation; & when once attached their whole life to the body of the fish on which they prey they never move again during their whole lives; but whilst in their embryonic condition, on the other hand they are furnished with eyes & actively swim about, with regularly well articulated limbs & seek their proper object to become attached to. The larvæ also of some moths are as complicated & more active than the perfect, but wingless & limbless females, which never leave their pupa- case, never feed, & never see the daylight.) ⁋

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(I think some considerable light can be thrown by the theory of descent on these wonderful & most general embryological facts in embryology, which are common in a greater or less degree to the whole animal & vegetable kingdom & in some measure to the vegetable kingdom;— on the fact, for instance, of the arteries in the embryonic Mammal & bird Reptile & Fish running & branching in nearly the same courses, & nearly in the same course manner with that of in the Fish full-grown fish; on the fact, of some embryos becoming less, instead of more, complicated during their maturity:— development;— on the fact, I may add, of the high importance to systematic naturalists of embryos a the characters & resemblances in the embryonic state of every organisms, in ascertaining its the true position in the Natural System of all mature organic beings. The following, are the considerations which throw light on these curious points.)

In the œconomy of, we will say, of a feline animal, the feline structure of the fœtus embryo & of the sucking kitten, is of quite secondary importance to it; hence, assuming for a time the possibility of variation, if a feline animal varyed (assuming for the time the possibility of this) & if some office place in the œconomy of nature favoured the selection of the a longer-limbed variety, it would be quite unimportant to the production by natural selection of a long-limbed breed, whether the limbs of the fœtus embryo & kitten were became long in a corresponding degree, if they became long enlongated were enlongated, if they did became so, as soon as the animal had to provide food for itself. Again And if a thethe period amount of variation of this or any other kind does not correspond in degree in the young after continued selection & the production of [illeg] which did not necessarily correspond in degree in the young & mature states of the new breed, and we have just seen it is [illeg] unimportant whether it does [illeg] or not;

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(A) which is wonderfully preserved, during the the production of infinitely numerous changes cells in the ever changing tissues,

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then it obviously follows, that if several species were produced & selected from one stock it does not necessarily follows that the young of these breeds should be as unlike, as will remain more like each other, than their mature parents. And again if An we suppose from two of these species two other groups of species to be selected, from & though adapted to widely different parts ends, in the same manner the young of the two genera would not differ from each other in a corresponding degree with their mature parents. Thus the greater resemblance or closer unity of type in the young than in the [3 words illeg] mature animals, would be explained. Before practically consi endeavoring to discover in our domestic breeds races, whether the structure & form of the young does has or does has not changed in an exact corresponding degree with the changes of full-grown animals of thei mature parent-breeds, it will be advisable to show that it is at least possi quite possible for the primary original germinal vesicle is often to be impressed with a tendency to produce a change some effect change on the growing & ever altering changing tissues, which sh will not be apparent fully effected till the animal is advanced in life.)

(From the following peculiarities of structure being inheritable,— namely general size, tallness not consequent on tallness of the infant) fatness either over the whole body or local,— change of colour in hair & its loss— deposition of d[illeg] boney matter on the legs of horses, blindness & deafness, that is changes of structure in the eye & ear— gout & consequent deposition of chalk-stone, & many other diseases as of the heart & brain &c &c producing organic changes more or less late in life; from all such peculiarities tendencies being inheritable we clearly see, that the germinal vesicle is impressed with some peculiarity power, (A) which after prod producing [2 words illeg] reproducing thousands of cells [illeg] (judging from the [2 words illeg] first forms known of life) [illeg] produced & reproduced, till the part ultimately to be affected is formed & the time of life arrived at. We see this clearly when we select a cow cattle with any peculiarity of their horns, or poultry with any peculiarity of their second plumage, for such

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itself. And if it were found, after continued selection & the production of several new breeds from one parent-stock, that the successive variations in each case, had supervened not very early in the youth or embryonic life of each breed (& we have just seen, that it is quite unimportant, whether it does so, or not), then it obviously follows that the young or embryos of each the several breeds would will continue resembling each other, more closely than their adult parents: And again, if from any two of these breeds, became each the parent-stock of several other breeds, forming two genera, the young & embryos of these would still retain remain more like than the when in an adult state

a greater resemblance to the one original stock, than when in an adult state. Therefore if it could be shown, that the period of the each every eac slight successive variation does not alwa always supervene at a very early period of life, the greater resemblance, or closer unity in type of animals in the young, than in the mature full-grown state would be explained. Before practically endeavoring to discover in our domestic races, whether the structure or form of the young has or has not changed in an exactly corresponding degree with the changes of the full-grown animals, it will be well to show, that it is at least quite possible for the primary germinal vesicle to be impressed with a tendency to produce some change on the growing tissues, which will not be fully effected, till the animal is advanced in life.)

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on an old one possessing certain characters, which, with a very slight modification, give it an adavantage over antogonist species forms, so in each quarter of the world allied species therefore partaking most characters in common will generally be undergoing modification together[illeg] & From the very same cause, the antagonist species, whose place who[illeg] who the new forms are whose place the new ones are in the act of displacement occupying, will generally be allied. & will therefore together become rarer & at last extinct. Hence The result of this will be, that allied species of the same genus will tend about the same time tend about the same time to become rarer & rarer in individuals & finally one after the other extinct, until the whole first genera dies a & finally even families become to is exterminated; & so will it be with successive genera, till the family is extinct. There will may, of course, be exceptions occasional exceptions. From what has gone before, we see that genera will appear by the slow & successive appearance formation of new species; & families by the slow will produce new genera, & the slow & scess formation of such groups, will form appearance appearance formation of new genera produce families. Now as far as our knowledge serves, it is in this remarkable manner, that groups of species appear on, & disappear from the face of the earth.)

I have here supposed extinction depends on new forms, which by no means follows.

I have begged case that a different species wd form 6 species

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(A) I must supect that at whatever period of life any in peculiarity (capable of being inherited) first becomes developed (whether from the action of external influences, or from some new affection of the germinal vesicle), this peculiarity tends to reappear in the offspring at a corrresponding period of life.

(A.)  In medical works it is asserted generally that at whatever period an heredetary disease appears in the parent it generallytends to reappear in the offspring at the same period.

(B).  a tendency in a disease to appear at particular stages of life can be transmitted through the germinal vesicles to different individuals of the same family.

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peculiarities do not cannot reappear till the animal is mature. Hence it is certainly possible that the germinal vesicle may be impressed with a tendency to produce a long-limbed animal, the length of whose limbs shall onl appear only when the animal is mature.) or even afterwards, they I know of no such fact this latter.

(In several of the cases just enumerated, we know that the first cause of the peculiarity, when not inherited, lies in the conditions to which the animal is exposed during mature life; thus to a certain extent general size & fatness,— lameness & blindness in horses, [illeg] & in a lesser degreee blindness, gout & some other diseases; and these peculiarities, when inherited reappear at the same time of life. (A)

Again For, Again, we find early maturity, the season of reproduction & longevity is transmitted to corresponding periods of life. Dr Holland has insisted much on children taking of the same family, exhibiting, certain diseases in similar & peculiar manners; my Father has known three brothers die in very old age of in a singular comatose state; now to make these cases strictly bear, the children of said families ought similarly to suffer at corresponding times of life in a similar manner; this is not known to be probably not the case, but the such facts show that (B)

it is possible that diseases, affecting widely different periods of life can be transmitted. So little attention is paid to very young domestic animals, that I do not know whether any case is on record of selected peculiarities in young animals, being for instance in the first plumage of birds, being transmitted onl to their young. There is one case, already

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alluded to, of calves with large hinder quarters reproducing similar calves, but then I do not know, whether or not the mature cattle were not also thus characterized. If, however, we turn to silk-worms, we find that the caterpillar, & cocoon (which must correspond to a very early period of the embryonic life of mammalia) vary & that these variations reappear in the offspring caterpillars or and cocoons. I think these facts are sufficient to render it probable that at whatever period of life any peculiarity (capable of being inherited) appears, (A)

it tends to reappear in the offspring at a corresponding period: (A) The same foregoing facts show show & presuppose that slight variations occur at nearly any various periods of life & after birth; and the science facts of Monstrosity on the other hand show that many changes take place in during fœtal life, before birth, for instance all such cases as extra fingers, hair-lip, & all great variations sudden & great alterations in structure; like & these, when inherited (B)

reappear before birth. during the fœtal embryonic life of the offspring. I will only add that at a still earlier period variations appear even in the eggs of animals, vary as in their size & sha shape & colour; & are possibly inheritable; at least as also, the capsule & membranes of the seeds of plants, also, vary greatly & are inheritable.

If then, the two following propositions are admitted (& I think the first can hardly be ad doubted) viz that variations of structure takes place at all times of life, though no doubt far less & fewer in in amount & seldomer in quite mature life (& then almos generally taking the form of disease); and secondly that these variations tend to reappear at to a corresponding period of life, which seems at least probable, then, we might a priori, have expected that in any selected breed, the f young animal would not partake in a corresponding

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(A)

, whether caused by the action of external influences during mature life, or from an affection of the primary of the germinal vesicle, it tends to reappear in the offspring at the corresponding period of life. Hence, I may add, whatever effect training, that is the full employment or action of any every newly selected slight variation, has in fully developing & increasing such variation, would only show itself, at in mature age, corresponding to the period of training; in the second first Chapter former Part, I showed that probably there was in this respect a marked difference in Natural & artificial selection,, man not regularly exercising or adapting his varieties to new ends, whereas selection by Nature presupposes such exercise & adaptation in the part each selected & changed. part.—

(B).  I will only add that at a period even anterior to embryonic life, namely during the egg-state, that varieties appear in size & colour (as with the Hertfordshire ducks with blackish eggs) & are inherited; which reappear in the egg; in plants, also, the capsule & membranes of the seed are very variable & inheritable.)⁋

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degree the peculiarities, characterizing the full-grown parent; though it would in a lesser degree. For during the thousand or ten thousand selections of slight increments in the length of the limbs of the individuals, necessary to produce a long-limbed breed; we might expect that such increments increments would take place in different individuals (as we do not certainly know at what period they do take place) some earlier & some later in the fœtal embryonic state & some during the early early youth; of the different individuals & their increments would reappear in their offspring only at corresponding periods. Hence the entire length of limb in the new long-limbed breed would only be acquired at the corresponding latest period of life, when that the latest a corresponding one which was latest, of the primary thousand primary increments of length supervened. And Consequently the fœtus of the new breed would during the production of such a breed woulld be much less changed during the early part of its existence from its original, & much less then the new breed from the original stock— the change supervening at the corresponding time with the earlier states part of its existence would remain much less changed in the proportions of its limbs from those of its parent-stock; and the earlier the period of its existence the less would its the change be.)

(Whatever may be thought of the facts on which this reasoning is grounded, it shows how the possibly the fœtus embryos & young of different species might come to remain less changed, than their mature parents; and practically if we find that the young of our domestic animals, though differing, differ less than their mature full-grown parents. Thus if we look at the young puppies of the Grey-hound &

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Bull-dog,— the two most artificial obviously selected modifyed of the breeds of dog,— we find their puppies, though at the age of six days, though with legs of the same length, & noses (measured from the eyes to the tip) of the same length, though in their proportional thicknesses & general appearance, there is a very great difference. So it is with cattle, though the young calves of different breeds are easily recognizable, yet they do not differ so much in their proportions, as the mature breeds full-grown grown animals. We see this clearly in the fact, that it shows to the highest skill to select the best form early in life, either in horses, cattle, or poultry; no one would attempt it only a few days hours after birth; & it requires great discrimination to judge with nice accuracy even durng their full youth, & the best judges are sometimes deceived. This shows that the ultimate proportions of the body are not acquired till late in life near mature age. If I had collected sufficient facts firmly establish the proposition, that in an artificially selected breeds, the embryonic & young animals are not changed in a corresponding degree with their mature parents, I might have omitted all the foregoing reasoning, & the attempts to explain how this happens; for we might safely have transferred the proposition to the breeds or species Naturally Selected; and the ultimate effect would

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necessarily have been that in a number of races or species animals, forming several genera & families, descended from a common stock, & forming several genera & families, that the embryos would have resembled each other more closely than mature full-grown animals, & the [illeg] facts of the hoof, hand, wing & fin, resembling each other in the embryo, simply results from the animals possessing these diverse different locomotive organs, having descended been selected from the same parent stock. the variations ha not having supervened in the earliest periods of it's embryonic existence. Whatever may have been the form or habits of the parent-stock of the Vertebrata, — in whatever course its arteries run & branched, the selection of variations supervening after the first formation of arteries in the embryo, would not tend to alter exce except indirectly their course of the arteries at course at that period; hence the similar course of the arteries in the Mammal, Bird, Fish & Reptile & Fish, must be looked at as, a the most ancient record of the course in the embryonic structure of the common parent-stock of these four great classes.

A long course of selection might cause a form to become more simple, as well as more complicated;— thus the adaptation of a crustaceous animal to live by suction attached during its whole life to the body of a fish another animal & by the suction of its [illeg] might permit with advantage great simplification of structures; & on this view, in which case,

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the singular fact of an more complex forms of the embryo, being more complex than its parent is at once explained. I may take this opportunity of remarking that Naturalists have observed that in most of the great classes, a series exists from very complicated to very simple beings;— thus in Fish, what a range there is between the Sand-eel & shark — in Crabs Crustaceans the Articulata between the commmon Crab & the Daphne — in insects—, between the aphis & butterfly,— & between the mite & a [illeg] a spider. Now the observation just made, namely that selection might tend to simplify, as well as to complicate, : explains this; for we can see, that during the endless geologico-geographical changes & consequent isolation of species, a station occupied in other districts by lower less complicated animals might be fil left unfilled & be occupied by a degraded form of a higher or more complicated class; & it would by no means follow that when the two regions became united that the degraded though higher organism would give way to the naturally aboriginally lower organism. (A) According to our theory, there is obviously no power tending constantly to exalt species, though beyond except the mutual struggle of between the different individuals & classes; though but from the strong & general, [illeg] tendency, we might expect to find some tendency to progressive complication in the successive creations productions of new organic beings forms.)

(In an early part of this discussion section, I stated that the forms, for instance I have above remarked that the feline form, is quite of secondary importance to the fœtus embryo & to the young animal. Of course kitten. Of course

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(A) seeing how similar in general appearance & colours habits, the, one of the Snake-like order, is to an earth worm, it is not difficult to imagine that these widely-separated animals might come to be antagonist species

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during any great & prolonged change of form structure in the mature animal, it wo might or often would be indispensable that certain changes the forms of the fœtus embryo should be changed, & this could be effected, owing to the effected, which by selection, & the heredetary tendency at corresponding ages, by selection, equally well as in mature age: thus if the fœtus embryo tended to become or to remain, either over its whole body or in certain parts too large, bulky, the female parent would die or suffer more during her confinem parturition; & as in the case of the calves with large hinder quarters, the peculiarity must be either elimanated, or the species become extinct. Where an embryonic form has to seek its own food, its structure & adaptation is just as important to it, the species, as that of the mature full-grown animal; & and as we have seen that a peculiarity, appearing in a caterpillar, or in a child, (as shown by the heredetariness of peculiarities in the milk-teeth) at any time of life reappears in its offspring, so we can at once see, that our common principle, of the selection of slight variations accidental variations, n[illeg] would alter, modify, & adapt a caterpillar to the new or changing conditions, precisely as in mature animals. the full-grown cater butterfly. Hence probably it is that caterpillars of different species of the Lepidoptera, differ more than those embryos of the do, at a corresponding early period of life, which remains inactive in the wombs of their parents. The parent during successive ages continuing to be being adapted by selection for some one object, & the larva for quite another one, we need not wonder at the difference becoming wonderfully great between them, even as great as between the fixed Rock-barnacle, & its free, crab-like offspring, furnished with eyes , & well articulated locomotive limbs.—)

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(It follows strictly from the above reasoning only that the embryos of existing, for instance, existing mammifers vertebrata, resemble more closely the embryo of the parent-stock of this great class, than will full-grown existing mammifers vertebrata resemble their full-grown parent-stock. But it may be argued with much probability, that in the earliest & simplest condition of things that the parent & embryo would always resemble each other, & that the passage through embryonic forms is entirely due to modifications subsequent variations affecting only the late states more mature periods of life. If so, the embryos of the existing mammifers vertebrata will shadow forth the full-grown structures of the one some of the earliest parent-stocks forms of this great class, which existed at the earlier periods of the earth's history: Such parent-stocks must have existed at an most immensely remote epoch,: and accordingly animals with a fish-like animals structure ought to have preceded

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(We are now prepared to under perceive, why, if the a genealogical arrangement of organic being would be, as I have attempted to show, solve the enigma of what constitutes the Natural System, why the study of embryonic forms is of such acknowledged importance in classification, (A) [words illeg] that during the selection [illeg] of mature full-grown animals to the most diverse habits, there is a less power & less tendency to alter the young & hence we might expect to find preserved in this state similarities, which would be quite lost & obscured in the mature life. the full-grown animal. I conceive it would be impossible to offer any explanation of the view of absolute creation, [illeg] the plaines affinities of organic beings thus being plainest & of the greatest importance at that period of life, when the they are their structure is not adapted to the final part, they have to play in the œconomy of nature.)

(It [illeg] follows from the above reasoning, that the embryonic forms of, the parent, (we will say),, for instance, the existing mammifers, of their common parent-stock, & of all intermediate forms, beings, would resemble mammifers, would much probably would resemble each other much more closely than do the mature states of the existing, intermediate & parent would do would these same beings, if known, in their mature state. But as it may be argued, if we choose to go hypothetically to a still earlier states, condition of things, that the original parent [illeg] [illeg] probably passed resembled in some degree its still preserved embryonic form; & cause of every any organic beings passing through embryonic & differently organized states stages, with a very different organization,

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For we have seen that a variation, supervening at any time, may aid in the adaptation modification & adaptation of the full-grown being, but for the modification of the embryo, only the variations must which supervene very at a very early period can be seized on & perpetuated seized upon by selection; hence there will be less power, & less tendency (for the structure of the embryo is mostly unimportant) to modify the young; & hence we might expect to find at this slate period to find similarities preserved between different groups of species, which had been obscured & quite lost in the full-grow grown animals. I conceive on the view of separate creations, we it would be impossible to offer any explanation of

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(We are now prepared to under perceive, why, if the a genealogical arrangement of organic being would be, as I have attempted to show, solve the enigma of what constitutes the Natural System, why the study of embryonic forms is of such acknowledged importance in classification, (A)

[words illeg] that during the selection [illeg] of mature full-grown animals to the most diverse habits, there is a less power & less tendency to alter the young & hence we might expect to find preserved in this state similarities, which would be quite lost & obscured in the mature life. the full-grown animal. I conceive it would be impossible to offer any explanation of the view of absolute creation, [illeg] the plaines affinities of organic beings thus being plainest & of the greatest importance at that period of life, when the they are their structure is not adapted to the final part, they have to play in the œconomy of nature.)

[pinned insert:] (It follows strictly from the above reasoning only that the embryos of existing, for instance, existing mammifers vertebrata, resemble more closely the embryo of the parent-stock of this great class, than will full-grown existing mammifers vertebrata resemble their full-grown parent-stock. But it may be argued with much probability, that in the earliest & simplest condition of things that the parent & embryo would always resemble each other, & that the passage through embryonic forms is entirely due to modifications subsequent variations affecting only the late states more mature periods of life. If so, the embryos of the existing mammifers vertebrata will shadow forth the full-grown structures of the one some of the earliest parent-stocks forms of this great class, which existed at the earlier periods of the earth's history: Such parent-stocks must have existed at an most immensely remote epoch,: and accordingly animals with a fish-like animals structure ought to have preceded

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parent-stock of each class,

in each class, the parent-stock, which lived at the most remotest epoch, must have

the forms earliest produced in each class w ought to resemble the existing embryonic forms

of the same class

in each class the forms produced at the earliest earlier periods of the earth of the earth's history ought to resemble the the now existing embryonic forms of the same class;

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beings in the original parent stock having [illeg]d, having [illeg] mature had [illeg] embryonic an organization, since became [illeg] became embryonic. According to this view (A) the earliest first produced animal of every class, ought to resemble [illeg] degree a parent [2 words illeg] & therefore the fish-like animals ought to have preceded [illeg] Birds & Mammalia; & of fish, that higher organized division with the vertebra extending into one division of the tail, ought to have preceded the equal-tailed, because the young embryos of the latter have an unequal tail; & of crustaceæ, the entomostraceous entomostraca ought to have preceded the ordinary crabs & barnacles— polypes ought to have preceded jelly-fish; & infusorial animalcules before both. these latter. This order of precedence in time in some of these cases is believed to hold good; but I wish think, that our evidence is so exceedingly incomplete, regarding what the number & kind of, organisms that have existed during all, especially the earlier, periods of the earth's history, that I should put a stress on this accordance, even if it held truer, than it probably does in our present state of knowledge.)

Chapt. VI

Abortive or rudimentary organs

Organs This is our [words illeg] or Parts of the structure are said to be "abortive", or when in a still lower state of development, "rudimentary", when they the same reasoning power, which shows convinces us that they are in other in some cases similar parts they are eminently useful & beautifully adapted to certain ends, declares that in these others they are absolutely useless. Thus the Rhinoceros, the Whale &c have

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, when young, small, but normally properly formed teeth, which never protrude from the jaws:— certain bones & even the entire extremities are represented by mere little cylinders or points of bones, often [illeg] soldered to other bones: many beetles have exceedingly minute, but regularly formed wings lying under their wing cases, which are united never to be opened: stamens are many plants have instead of stamens, mere filaments or little knobs; petals are reduced scales, &the whole flowers to e buds, (as in the feather hyacinth) which never [illeg] expand. Other Similar instances are almost innumerable; & are justly considered wonderful: probably scarcely one organic being exists, in which some part does not bear the stamp of inutility; for what can be clearer, as far as our reasoning powers can reach, than that teeth are for eating, extremities for locomotion; wings for flight, stamens & the entire flower for reproduction; yet for these clear ends, the parts in questionare manifestly unfit. Abortive organs are often said to be mere representations (a metaphorical expression) of the similar parts in other organisms; organic beings; but in some cases they are more than representatives, for they seem to be the actual organ not fully grown or developed: thus the existence of mammæ in the male vertebrata is one of the oftenest adduced cases of abortion; but w[illeg] we know that these organs in man & in the Bull have performed their proper function & secreted milk: the cow has normally four mammæ & two abortive ones, but these latter in some instances give milk; again in flowers the representatives of stamens & pistils can be traced to true be really these tr parts not developed; Koelreuter has shown that the by crossing a diœcious plant (a Cucubalus)with a having a

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: when morphologists show that the skulls jaws mouths of insects consist of metamorphosed legs, they

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rudimentary pistil, with another hermaphrodite species, having this organ perfect, that in the hybrid offspring, the rudimentary part is more developed, though still remaining abortive; now if this shows how intimately related in nature the mere rudiment & the fully developed pistil must be.) ⁋. Abortive & rudimentary organs,

⁋. (Abortive organs which must be considered as useless as far as their ordinary & normal [illeg] purpose is concerned, are sometimes adapted to other ends: thus the marsupial bones, which properly serves to support the young in the mother's pouch, are present in the male, but these and serve as the fulcrum for muscles connected only with male functions: in the female male flower florets of the marigold, the pistil is abortive , but for its proper end, but serves to sweep out the pollen from out of the anthers, ready to be borne by insects to the true & active perfect pistils in the other florets. (A) It is likely that in many cases, yet unknown to us, that abortive organs perform some useful function; but in some, other cases, for instance in the teeth embedded in the solid jaw-bone, or in mere knobs, the representatives rudiments of stamens & pistils, the boldest imagination will hardly venture to ascribe to them any function. Abortive parts, even when wholly useless to the individual species, are of great signification in the System of Nature, for they are often found to be of very high importance in the a Natural classification; thus the presence & position of entire abortive flowers in the grasses cannot be overlooked in attempting to arrange them naturally according to their true affinities. This corroborates a statement in the last a previous chapter, that the physiological importance of a part is no index of its importance in classification. Finally I believe abortive organs

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are, proportionally with other parts, [illeg] most & often only [illeg] developed, and often only only in the embryonic or young state of each species: this again, especially considering the classificatory importance of abortive organs is evidently part of the same law, (stated in the last chapter) that the higher affinities of organisms, are often best seen in the Young embryonic or young state. stages, through which the embryo passes. On the ordinary veiw of individual creations, I must think, that no scarcely any class of facts in the Natural History, are more wonderful or less capable of receiving explanation.)

Physiologists apply the term abortion in a somewhat diffferent sense from Naturalists; & their sense application is probably the primary one; namely to parts, which from accident or disease during the embryonic period before birthare not developed or do not grow: thus when a young animal is born with little stump in the place of a finger or extre of the whole extremity or with a little button instead of a head, or with mere bead of bony matter instead of a tooth, or with a stump instead of tail, these parts are said to be aborted. Naturalists, however on the other hand, as we have seen, apply this term to stunt parts, not altered which as are not stunted & during the growth of the embryo, but which are as regularly produced in successive generations, as any other parts, essential to the life of the individual: Naturalists, therefore, use this term in a metaphorical sense. This These two classes of facts, however, blend into each other; by parts accidentally aborted during the embryonic life of one individual

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being often (when possible with the preserv transmitted to successive becoming heredetary in the succeeding generations: thus a cats or dogs cat or dog born with a a stump instead of a of a tails, tends to transmit stumps to their offspring; & so it is with similar parts stumps representing the extremities; & so again with successive buds def flowers with defective & rudimentary parts annually produced, & even with fresh successive seedlings. The strong heredetary tendency to reproduce every congenital & slowly acquired structure, whether useful or injurious to the individual has been shown in the first Part, so that we need feel no surprise at these primarily truly abortive parts becoming heredetary. A curious instance of the force of heredetariness is sometimes seen in [illeg] two little loose hanging horns, quite useless as far as the function of a horn is concerned, being produced in hornless races of our domestic cattle. We shall have immediately to consider the probability of a part gradually lessened by continued selection & not used, becoming abortive & heredetary the rudiment heredetary being inherited.

NowNow I believe no real distinction can be drawn between  the a stump representing a tail or a horn or the an extremeties, a short, shrivelled stamen without any pollen, or a dimple in a petal representing a nectary, when such useful parts are regularly reproduced in a race or family, & the true abortive organs of Naturalists. And if we had reason to believe (which I think we have not) that all abortive organs could of were at some period have been suddenly produced during the embryonic life of an individual, & then afterwards become her inherited, we should at once have a

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simple explanation of the origin of abortive & rudimentary organs. (A)

& we should [illeg] how it [illeg] that parts useless to the individual are of high importance in a Natural or geneological classification, from revealing one point of the structure of in the parent form;— as, during changes of pronunciation, the [2 words illeg] certain letters [illeg] useless [illeg] sound, may aid [illeg] in understanding their derivation.

 

(There seems to be some probability that continued selection of disuse of any part or organ & the selection of individuals with such parts slightly less developed, would in the course of ages produce in organic our domestic organisms beings, under domesticity, races with such parts abortive. We have every reason to believe that every part & organ becomes fully developed, only with exercise exercise of its function, in in a somewhat lesser degree with less exercise, & if forcibly precluded from all action, such parts will often become atrophied. If the eye is injured early in life, the optic nerve sometimes becomes absorbed: Every peculiarity, let it be remembered, tends, especiallywhere both parents have it, to be inherited. The less power of flight in the common duck compared with the wild, can hardly must be partly attributed to disuse during successive generations; & if as we must look at and as the wing is properly adapted to flight, we must consider our domestic duck in the first stage towards the state of the Apteryx, in which the wings are

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In the same manner as during changes of pronunciation, certain letters in a word may become useless in sounding pronouncing it, but yet may aid us in searching for its derivation, so we can see that rudimentary organs, may become useless to no longer useful to the individual, may be of high importance in ascertaining its descent, that is, its true position classification in the Natural Classification System.)

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so curiously abortive. Some naturalists have attributed & possibly with truth the falling ears, so characteristic of most domestic dogs, some rabbits, oxen, cats goats, horses &c &c, as the effect of the lesser use of the flex muscles of their flexible parts, during succcessive generations of inactive life; & muscles which cannot perform their functions must be considered as verging towards abortion. In flowers again we see the gradual abortion during successive seedlings (though this is more properly a conversion) of stamens into imperfect petals & finally into perfect petals. When the eye is blinded in early life, the optic nerve sometimes becomes atrophied; may we not believe that where an this organ, as is the case with the eyes of the subterranean Tuco-tuco, is constantly very frequently impared & lost, that in the course of generations the part whole organ would become abortive, as it normally is in some sub burrowing quadripeds?, having nearly similar habits with the Tuco-tuco.?) ⁋

(In as far, then, as it is admitted as probable, that the effects of disuse (together with occasional true embry abortions in the embryonic period) would finally cause a part to be less developed & finally to become abortive & useless (if a part can be called useless, which in the each particular instance is it may be presupposed if present, would be of no of any use); not to be used, then, during the infinitely numerous changes of habits in the many descendants from a common stock, we might fairly have expected that cases of organs become abortive, would have been as numerous. as they usually are in Nature. The preservation of the stump of the tail, as usually happens when an animal is born tailless, we

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can only explain by the strength of the heredetary principle; but on the theory of disuse, gradually obliterating a part, we can see on according to the principles explained in the last section chapter ( of heredetariness at corresponding periods of life, together with the use & disuse of the structure any organs all not being generally brought into play towards in early or embryonic life, ( that organs would tend only to be reduced to that state, in which it they exist in early early embryonic life. Moreover we can thus see, why abortive organs are proportionally ones most developed as exclusively only at this an early period. Again by gradual selection, we can see, how an organ might become rendered atrop abortive in its primary use, might be converted to other uses;— purposes; a duck's wing might come to serve for a fin, as does that of the Penguin— an abortive bone might come to serve, by the slow increments & change of place in the muscles, muscular fibres as a fulcrum for a new set— a new series of muscles; the pistil of the Marigold might become abortive as a reproductive part, but be continued in its function of sweeping the pollen out of the anthers; for if, in this ot latter other case, the abortion had continued not been checked by selection, the species must have become extinct from the pollen remaining enclosed in its capsules.)

(Finally then, I must repeat, that the this wonderful fact, of organs created in for beings, both those now alive & those buried in the deepest antiquity, during countless ages, being present both in living & long extinct beings formed with traces of exquisite care, but now which organs are either now absolutely useless, or adapted

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to ends wholly different from their ordinary use end,— which are generally best developed at an early period of life, & which are full of signification in attempting the Natural Classification,— which abortive organs are being present & forming part of the structure of almost every organic being both in present recent & long-past times,— these wonderful facts not only receive a simpler explanation on by the theory of descent or even long-continued selection of many forms from a few common parent stocks, but necessarily follow from this theory. If we this theory be rejected, this view these facts in remain quite inexplicable;— without indeed we remain call rank as an explanation, such loose metaphors, as that of Decandolle's, in which the Kingdom of Nature is compared to a well covered table, & the abortive organs are considered as put in for the sake of symmetry!—

Chapter VII

(Recapitulation) and Conclusion.

I will now briefly recapitulate the course of this work. In the First Part Chapter we have seen that most, if not all, organic beings, when taken by man out of their natural conditions, & bred during several generations, vary: that this variation is partly due to the manner in which direct effect of the new external influences affect & partly to their indirect effect of the parents transmitting less exact likeness to their offspring, than offspring being produced less exactly like their parents than usually happens in the wild state & consequently to on the reproductive system, making the organization of the offspring thus exposed, in some degree plastic. Of the variations thus produced man when uncivilized naturally preserving, & therefore breeding from, preserves the life & therefore unintentionally breeds from those individuals

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(Finally then, I must repeat that these wonderful facts, of organs formed with traces of exquisite care, but now either absolutely useless or adapted to ends wholly different from their ordering and, being present & forming part of the structures of almost every inhabitant of this world, in long-past & present times,— being best developed & often only only discoverable at a very early embryonic period, and being full of signification in arranging the long series of organic beings in a natural system— these wonderful

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(Finally then, I must repeat that these wonderful facts, of organs formed with traces of exquisite care, but now either absolutely useless or adapted to ends wholly different from their ordering and, being present & forming part of the structures of almost every inhabitant of this world, in long-past & present times,— being best developed & often only only discoverable at a very early embryonic period, and being full of signification in arranging the long series of organic beings in a natural system— these wonderful

organic being both in present recent & long-past times,— these wonderfulfacts  not only receive a simpler explanation on by the theory of descent or even long-continued selection of many forms from a few common parent stocks, but necessarily follow from this theory. If we this theory be rejected, this view these facts in remain quite inexplicable;— without indeed we remain call rank as an explanation, such loose metaphors, as that of Decandolle's, in which the Kingdom of Nature is compared to a well covered table, & the abortive organs are considered as put in for the sake of symmetry!—

Chapter VII

(Recapitulation) and Conclusion.

I will now briefly recapitulate the course of this work. In the First Part Chapter we have seen that most, if not all, organic beings, when taken by man out of their natural conditions, & bred during several generations, vary: that this variation is partly due to the manner in which direct effect of the new external influences affect & partly to their indirect effect of the parents transmitting less exact likeness to their offspring, than offspring being produced less exactly like their parents than usually happens in the wild state & consequently to on the reproductive system, making the organization of the offspring thus exposed, in some degree plastic. Of the variations thus produced man when uncivilized naturally preserving, & therefore breeding from, preserves the life & therefore unintentionally breeds from those individuals

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most useful to him in his different con states. or as he when does in a civilized state to his intenionall intentionally selecting & separating such individuals & breeding from them (A)

When several breeds are once formed, their crossing is the most fertile source of new breeds. Perfectly free crossing, however, will tend to obliterate breeds. Their Variation must be ruled, of course, by the necessity health of the new race; & its kind by the tendency to return to the ancestral forms & probably by many unknown laws, determining the proportional increase & symmetry of the body. & likewise by the tendency to return to the former structure. The amount of variation which has been effected under domestication is quite quite unknown in the majority of domestic organisms. beings.)

In the Second Chapter it was shown that wild organisms undoubtedly vary in some slight degree; & that the kind of variation, though much less in degree, is similar to that of domestic organisms. It is highly probable that every wild organic being, if kept subjected during several generations to new & varying conditions would vary. It is certain that during the course of ages the conditions in some countries must vary in almost every possible manner; organisms living in an isolated country, undergoing geological changes must in the course of time be so subjected to new conditions; moreover an organism by when by chance might would must sometimes be born transported into a new station, for instance into an island, will often in which it could would often wd survive but yet be exposed to new conditions & be surrounded by a new set of other organisms. series of organic beings. If there was no power at work selecting the any every slight variations, while exposed & opened which opened new sources of subsistence to the organic beings, a being thus situated, the effects of crossing & the constant tendency to reversion to the old parent-form, would prevent the production of new races. If there were any selective agency at work, it seems impossible to assign any limit to the complexity & beauty of the adaptive structure, which might then be produced; for certainly the limit of possible variation of organic beings is not kno either in a wild or domestic state is not known. It was then shown that from the geometrically increasing tendency of each species to multiply (as evidenced from what we know of mankind & other animals when favoured by circumstances) & from the means of subsistence of each species on an average remaining constant, that during some part of the life of each, or during every few generations, there must be a severe struggle for existence, & that a grain in the balance is will determine which individuals shall live & which perish. In a is country, therefore cut of from free immigration, undergoing changes, & with new stations opening, & with undergoing changes & with new

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(A){ : when civilized, he intentionally separates & breeds from such th such individuals. most useful to him.

Every part of the structure seems occasionally to vary in a very slight degree & the degree extent to which all kind of peculiarities in mind & body, when congenital or when slowly acquired by [illeg] from external influences, from exercise, & from disuse, is truly wonderful.

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(AA) for  it is found that when individual of animals & plants are placed under new conditions, they are found to become, without losing their healths, to become as sterile in the same manner & to the same degree as are hybrids; & it is conceivable that the cross between true species with different constitutions, would be in nearly the same relation to the external conditions, as when the parent species, when are bodily taken out of their proper sphere. have its constitution affected in the same peculiar manner, as when an individual animal or plant is placed under new conditions.

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stations may forming, if cut off from the free immigration of species better adapted to the new station & conditions, thus formed it cannot be doubted that there is a most powerful means of selection, seizing preserving tending to preserve every even the slightest variation, of in which aided aiding the subsistence or preservation defense of those organic beings, whose organisation had been rendered in any some degree plastic. Moreover in animals, in which where the sexes are distinct there will is a sexual struggle, by which the most vigorous & bes males, on & therefore will hav most vigorous & consequently best adapted will oftener procreate their kind. A new race thus formed by natural selection would be indistinguishable from a species: For comparing on the one hand the so-called several species of a genus ,with on & on the other hand, several domestic races from a common stock, we find we cannot discriminate them by the amount of external difference, but only by thos each of the domestic races not remaining so constant or being as 'true', as [illeg] species [illeg] do, are, & by their being always producing fertile offspring when crossed. It And it was then shown that a race naturally selected, would from the selected variation being slower, from no part change the selection not being capricious steadily aiming tending towards the same ends & from every new slight change in structure being adapted (, as is implied by its selection) to the new conditions & being fully exercised, & lastly from the absence of freedom from occasional crosses with other races, we would almost necessarily be "truer", than a race formed selected by ignorant, or capricious & short-lived man. With respect to the sterility of species, when crossed, it was shown not to be a universal character & when present & to been gradu in a series more or less exist in a more to vary in respect degree: it Sterility was shown probably to depend, less on external, than on constitutional differences; rather (AA) than on extern[illeg] Man in making having selecting domestic races has little wish & still less power to adapt the whole frame to new conditions; moreover there seems no sort of necessary in nature, where; in nature, however, where each species survives survives by a struggle against other species & external nature it had been must have be very different. The offspring of domestic races propagation of different races together of different bred together or of those offspring that is of mongrels, & Hybrids of hybrids, that is the offspring of species when partially fertile, were compared, & they were their character & the

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being [text excised]

might be expected from [text excised]

continents. It is also said, that the Flora of the Pacific is more Indian than American, although America lies in the direction from

which the trade-winds blow & is somewhat nearer, but be it observed that the heaviest gales

[text excised] Pacific are opposed to the trade-wind

[text excised] side. The [text excised] extent

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Races of the same species were also then compared with species of the same genus, and they were found to present some striking analogies. The offspring, also, of races when crossed, that is mongrels were compared with the crossbred offspring of species, that is hybrids, & they were found to resemble each other in every all their characters, with the one exception of sterility, & even this when present often becomes after some generations variable in degree.

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stations may forming, if cut off from the free immigration of species better adapted to the new station & conditions, thus formed it cannot be doubted that there is a most powerful means of selection, seizing preserving tending to preserve every even the slightest variation, of in which aided aiding the subsistence or preservation defense of those organic beings, whose organisation had been rendered in any some degree plastic. Moreover in animals, in which where the sexes are distinct there will is a sexual struggle, by which the most vigorous & bes males, on & therefore will hav most vigorous & consequently best adapted will oftener procreate their kind. A new race thus formed by natural selection would be indistinguishable from a species: For comparing on the one hand the so-called several species of a genus ,with on & on the other hand, several domestic races from a common stock, we find we cannot discriminate them by the amount of external difference, but only by thos each of the domestic races not remaining so constant or being as 'true', as [illeg] species [illeg] do, are, & by their being always producing fertile offspring when crossed. It And it was then shown that a race naturally selected, would from the selected variation being slower, from no part change the selection not being capricious steadily aiming tending towards the same ends & from every new slight change in structure being adapted (, as is implied by its selection) to the new conditions & being fully exercised, & lastly from the absence of freedom from occasional crosses with other races, we would almost necessarily be "truer", than a race formed selected by ignorant, or capricious & short-lived man. With respect to the sterility of species, when crossed, it was shown not to be a universal character & when present & to been gradu in a series more or less exist in a more to vary in respect degree: it Sterility was shown probably to depend, less on external, than on constitutional differences; rather (AA)

than on extern[illeg] Man in making having selecting domestic races has little wish & still less power to adapt the whole frame to new conditions; moreover there seems no sort of necessary in nature, where; in nature, however, where each species survives survives by a struggle against other species & external nature it had been must have be very different. The

[pinned insert:] Races of the same species were also then compared with species of the same genus, and they were found to present some striking analogies. The offspring, also, of races when crossed, that is mongrels were compared with the crossbred offspring of species, that is hybrids, & they were found to resemble each other in every all their characters, with the one exception of sterility, & even this when present often becomes after some generations variable in degree.

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(A)

laws of their propagation we found, to be exactly the same, with the one exception of their fertility sterility, in itself a very variable & even the degree of this often becomes, after some generations, very variable. The Chapter was then summed up by the admission, that although it seems highly probable, that races, indistinguishable in any one important character from so-called species, are occasionally produced in certain situations on our changing world; yet that we must look for our direct evidence, to the relations in the past & present geographical distributions, in the affinities, & in the structures of the infinitely numerous beings by which we are surrounded on all sides.

In [illeg] N[illeg] In the Third Chapter, for convenience sake the consideration of, the inheritable variations in the mental-phenomena of wild & domestic & wild organic beings, were for convenience sake jointly considered. It was shown, that we have nothing to are not concerned with their first origin of the leading mental qualities, but that tastes, passions, dispositions, consensual movements, & habits & what m all becomes either congenitally or during life mature life modifyed & were are inherited. Several of these modifyed habits were found to correspond in every essential part character with true instincts. These modifyed Mental phænomena were tested by comparing the effects of crossing, t[illeg] with true the true instincts, & they were found to follow the same laws. Instincts & dispositions &c are fully as important to the preservation preservation & increase of a species, as its corporeal corporeal structure, & therefore the natural means of selection would equally well act on & modify

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The chapter was then summed up & it was shown that there is no ascertained limit to the amount of variation, with due time & changes of conditions granted, is known. It was then admitted that although the production of new races, indistin=guishable from true species is probable, we must look for direct evidence to the relations in the past & present geographical distribution of the infinitely numerous beings, by which we are surrounded, to their afffinities, & to their structure, for any direct evidence.)

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them, equally with corporeal structure. This being granted, as the well as the proposition, that mental phænomena are mos variable & that the modifications are inheritable; the possibility of the several most complicated instincts being slowly acquired was considered, & it was shown, from the very imperfect series in the instincts of the animals now existing, that we are not justifyed in primâ facie, rejecting a theory of the common descent of allied organisms, from the difficulty of imagining the transitional stage in the various now most complicated & wonderful instincts. We were thus led on to the consider the same questions with respect both to sop highly complicated organs, & to complicated the aggregate of several such organs, that is individual organic beings, & it was shown by the same method of taking the existing most imperfect series, that we ought not at once to reject the theory, because we cannot trace the transitional stages in such organs, or conjecture the transitional habits of such the such individual species.)

In the Second Part, the direct evidence of allied species & groups of species having descended from the same stock was discussed. It was shown that this theory requires a long series of intermediate forms between the species & groups in the same classes,— forms not directly intermediate between existing species, but intermediate with the a common parent. It was admitted that if even all the preserved fossils or existing species were collected, such a series would form be far from being formed; but it was shown that we have no good evidence, that the oldest known deposits are contemporaneaous with the first appearance of living beings, or that the several subsequent formations

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are nearly consecutive, or that any one formation possess preserves a nearly perfect Fauna of an even the hard marine organisms, living in that quarter of the world. The extreme improbability of a perfect record ever being preserved, was thus shown in detail; and Consequently that we have no reason to suppose that more than a small fraction of the organisms which have lived at any one period, will have ever been preserved; & hence that we cannot ought not to expect to trace discover the fossilized sub-varieties gradations between any two species. On the other hand, the evidence, though extremely imperfect drawn from fossil remains, as far as the little way it does go, is in forms of the past existence of a such a series of organisms, having existed, as that required. This want of evidence of the past existence of almost infinitely numerous of intermediate forms is, I conceive, much the weightiest difficulty on the theory of common descent, but I am convinced it is due to our necessary ignorance necessarily resulting from the imperfection of all geological records.)

 

(In the second Chapter, it was shown that new species gradually appear, & the old ones disappear from the earth, which strictly accords with our theory. The extinction of species seems to be preceeded by their rarity, & on this view is not nearly so wonderful as has been supposed. no one ought to feel more surprise at a species being exterminated than at its being rare. Every species, whose numbers which is not increasing in number must have its geometrical tendency to increase, checked by some agency, generally quite imper seldom accurately perceived by us. Each slight increase in the power of this unseen power agency would cause a corresponding decrease in the average average numbers of that species, & it is become rarer: we feel not the least surprise at one species of a genus being rare & another numer abundant; why then shd we be surprised at its extinction, when we have good

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reason to believe that rarity is as at least generally its precursor, as illness is to the death of the individual.

(A); namely the dissimilarity

in areas widely & effectually separated, of the organic beings inhabiting exposed to very similar conditions, as for instance within the tropical forests or on the dependent volcanic islands, of Africa & S. America; and on the other hand, the comparatively close similarity in an area less effectually divided; of the organic beings also exposed to widely very dissimilar conditions, within the same [illeg] area; —; also, the dissimilarity also of the inhabitants on the opposite sides of barriers within the same area or continent or on different islands of the same archipelago, whether exposed to very similar like or dissimilar unlike conditions; this dissimilarity, however, even when the conditions are quite of the inhabitants of the same continent, even even under conditions quite unlike, is so much less in degree than that dissim between the inhabitants of distinct continents even under conditions quite very like, that it may be comparatively be called a similarity;— again

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reason to believe, that this very rarity is its regular precursor & method. cause.)

(In the Second Third Chapter, the leading facts in geographical distribution of organic beings

were considered;— — namely that (A)

the dissimilarity of the organic beings under similar conditions in areas widely separated as in the tropical districts or on the alpine volcanic islands of two continents & their greater similarity even under under the most opposite conditions on the same continent where the areas are ne less effectively separated— their differences on opposite sides of barriers in the same continent, & on different islands in the same archipelago, with their general relations to the continent of which they form part

the peculiar peculiar relations of alpine flora;— the absence of mammifers on isolated the smaller, isolated islands & the comparative fewness of the other inhabitants plants & other organisms on islands with diversified stations;— the connexion between the possibility of occasional transportal from one country to another,, the with an affinity, though not identity of the organic beings inhabiting them;— the clear & striking relation between the living & the extinct in the same great divisions of the world; the In no persistence of & if; which relation, if we look still farther very far backwards, seems to die away. These facts, demonstrate that some quite organic beings have been created in their different regions in obedience to some, quite distinct laws for if we bear in mind the geological changes in progress, all simply follow from the proposition of allied organic beings having lineally descended ,through secondary metamorphoses from common parent-stocks. On the theory of independent creations, they must remain, isolated disconnected though evidently connected together, inexplicable & disconnected.)

(Brief instances)

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(In the succeeding next Third Fourth Chapter, the grouping of extinct & recent species— the appearance & disappearance of groups— the ill-defined object of the Natural Classification, not depending on the similarity of organs physiologically important having no relation to not being influenced by adaptive (though governing the whole œconomy of the individual) or analogical characters, but depending on any character which form not varies least & especially on much on the characters forms through which the embryo passes, &, was as was afterward shown, on ru abort the presence of rudimentary & useless organs,— — the alliance between the nearest species in distinct groups, not being general & not specific especial— the close similarity in the rules & objects in classifications classifying acknowledeged varieties races & species— all these facts were shown to follow, on the Natural System being a genealogical one. System.)

In the two Fifth, succeeding next Chapters, the unity of structure in the species of throughout large groups as species adapted to the most different lives. lives, and the wonderful metamorphosis (used metaphorically by naturalists) of one part or organ in another, were shown to follow simply on new species being produced by in the selection & inheritance of successive small changes of structure. The greater similarity of species of entire classes & smaller groups during the embryonic period, than during maturity.life The unity of type is wonderfully manifested by the similarity of structure, during the embryonic period, in the species of entire classes: to explain this, it was shown that the young of different races of our domestic animals were shown and found to differ less, during their young state, than during when full-grown; & it was shown that the remarkable similarity of all the species in during the embryonic period of the same throughout a whole classes, was would result might have and consequently, if species are produced like races, the same facts, on a greater scale, might have been expected to hold good with them. This remarkable

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(A) The importance of these embryonic resemblance, in making out a natural & genealogical classification, thus becomes at once obvious.

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law of nature was attempted to be explained, by through establishing by sundry facts, that sm slight variations first appear during all periods of life, & that when inherited, they tend to appear at the corresponding period of life; from according to these principles, the lesser variations of, in several species descended from the same parent stock, their embryos would almost necessarily much more closely resemble each other, & the embryos of the parent stock, than would these species when full-grown: (A)

The occasional greater simplicity of structure in the mature mature animal, than in the embryo,— the gradation in complexity of the species in the great classes— the adaptation of the larvæ larvæ of animals to independent powers of existence,— — the immense differences in certain animals in their larval & their mature states, were all shown on the above principles to present no seri difficulty.)

 

(In the last Chapter the frequent & almost general presence of organs & parts, called by Naturalists, abortive or rudimentary which though formed with exquisite care, are generally absolutely useless, though sometimes applied to uses not normal— which cannot be considered as representative parts, for they sometimes are capable of performing their proper function— which are always best developed & sometimes only developed during a very early period of life— & which are of admitted high importance in classification— were shown to be simply explicable & consequent on our theory of common descent.)

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[Leaves 219-227 are a different kind of paper from the rest of the document.]

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Thus have many general facts or laws been included under one explanation; & the difficulties encountered are [illeg] those which would naturally result from our acknowledged ignorance. And why should we not admit this theory of descent? Can it be shown that organic beings in a natural state are all absolutely invariable? Can it be said that the limit of variation or the number of varieties capable of production being formed under domestication are known? Can any distinct line be drawn between a race & a species? In To these those questions we may certainly say no. answer in the negative. As long as species were thought to be divided & defined by an impassable barrier of sterility; whilst we were ignorant of palæontology geology & had reason to suppose imagined that the world was of short duration & the number of its past inhabitants few, we were justifyed in assuming individual creation, or in saying with Whewell, that the beginnings of all things are hidden from man. Why then do we feel so strong an inclination to reject this theory, even whilst admitting that numerous intermediate (A)

I believe it is simply chiefly because we do not actually see & cannot because we are slow to admit any great change, of which we do not see the intermediate stages;

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; especially when (A) any the actual case of any two species or even races is p[illeg]t before adduced, & one is asked have these two, originally descended from the same parent womb? —

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because the mind cannot grasp the full meaning of the term of a million of years & cannot consequently add up & perceive the full effects of small successive variations. The difficulty, I believe is the same with that, which with most geologists it has taken years to remove, as when Lyell propounded that valleys were hollowed out by the slow action of the waves of the sea & of rivers. A man may long view the sea wearing the rock at the bottom of a cliff a grand precipice, without fully actually believing, though he may not deny it, that the great precipice, thousands of feet in thickness height of solid rock once extended miles over many square miles of space, where the open sea now rolls; without fully believing, that this same sea which beats the rock at his feet has been the sole removing power.)

What Shall we admit, then, allow that the three distinct species of Rhinocerous, which separately inhabit Java, Sumatra & the neighboring mainland of Malacca, were created male & female out of the inorganic materials of these countries? Without any adequate cause as far as our reason serves, shall we say, that, that they were from living near each other created very like each other or different so as to form a section of the genus, dissimilar from the African species, some of which inhabit very similar & some very dissimilar stations;— that they were created created on the same generic type with the ancient wooly Rhinoceros of Siberia & of the other species, which formerly inhabited the same main division of the world;— that they were created on

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less & less closely related types, but still with interbranching, types affinities with all the other living or extinct mammalia; ;— that without any apparent adequate cause their short necks should contain the same number of vertebræ with the giraffe; that their thick legs should be built on the same plan, with those of the antelope, of the mouse otter otter, of the hand of the monkey, of the wing of the bat & the fin of the porpoise;— that in each of the three species, the second bone of their leg should show clear traces of two bones being having been soldered & united into one; (A)

that in the jaws each, when dissected young, there should exist small teeth, which never come to the surface; that in possessing these useless, abortive teeth & in other characters these three Rhinoceroses in their embryonic state, should much more closely resemble other mammalia, than they do when mature; and lastly that in a still earlier period of life that their arteries should run and branch as if in a fish, to carry taking the blood to gills, which do not exist. as in a fish.— & that the complicated bones Now these three species of Rhinoceros closely resemble each other; more closely than many generally acknowledged races of our domestic animals; these three species, if domesticated, would almost certainly vary, & races, adapted to different ends, might be selected out of such variations. In this state they would probably breed together, & their offspring possibly would be quite, & probably in some degree

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;— that the complicated bones of their heads should become intelligible, if we imagine it to on the supposition of their having been formed of three expanded vertebræ.

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be less or more fertile; & in either case by continued crossing one form might easily be absorbed & lost in another. I repeat shall we then say that a pair or a gravid female of these three species of Rhinoceros were separately created, with deceptive appearances of relationship, with the stamp of inutility on some parts & of conversion in other parts, out of the inorganic elements of Java, Sumatra, & Malacca; or were have they descended, like our domestic races, from the same parent-stock? For my own part, I could no more admit the former proposition, than I could admit as readily admit, that that the planets move in their appointed courses, & that and a stone falls to the ground, not through the intervention of the secondary & appointed law of gravity, but from the direct volition of the Creator.)

 

(Before concluding, it will be well to show, although this has incidentally appeared, how far the theory of common descent can legitimately be extended. If we once admit that two good true species of the same genus can have descended from the same parent, it will not be possible to deny that two species of two genera may also have descended from common stock. For in some families, the genera approach almost as closely, as species of the same genus; & in some orders, for instance in the Monocotelydonous plants, the families run closely into each other. We do not

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hesitate to assign a common origin to dogs or cabbages, because they are divided into groups, analagous to the groups in nature. Many naturalists, indeed, admit that all groups are artificial; & they depend entirely on the extinction of intermediate species. Some naturalists, however, affirm, that though beaten driven from considereing sterility as the characteristic of species, that an entire incapacity to propagate together is the the only good best evidence of the existence of natural genera. Even if we lay put on one side the undoubted fact that some species of the same genus will not breed together, we cannot possibly admit such a the above rule, seeing that the grouse & pheasant (considered by some good ornithologists as forming two families) the bull-finch & canary-bird have bred together.)

 

No doubt the more remote two species are from each other, the weaker the arguments become in favor of their common descent.— In In species of two distinct families, the anga analogy from the variation of domestic organisms, & from the manner of their intermarrying fails, & the arguments from their geographical distribution quite or almost fail. But, if we once admit, the general principles of this work; as long far as a clear unity of type in groups of species as shown by

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adapted to play diversifyed parts independent of their adaptation to diverse parts in the œconomy of nature, can be made out, whether shown in the structure of the embryonic or mature animal, being, & especially if shown by a community of abortive parts, we are legitimately forced to admit their community of descent.. Naturalists dispute how widely this unity of type extends: all most, however, admit, that the Vertebrata are built on one type; the Articulata on another; the Mollusca on a third; & the Radiata on probably more than one. Plants, also appear to fall under three or four great types. On this theory, therefore, all the existing organisms, yet discovered, are descendants of probably less than ten parent-forms.—

(Conclusion)

My reasons have now been assigned for believing that specific forms are not immutable creatures. The terms used by Naturalists, of affinity, unity of type, adaptive characters, the metamorphosis & abortion of organs, cease to be metaphorical expressions & become intelligible facts. We no longer look at an organic being, as a savage does at a ship or other great work of

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art, as at a thing wholly beyond his comprehension, but we feel that its production has a history, & we are led to attempt to examine into it. How interesting do all instincts become, when we speculate on their origin, as heredetary habits or as slight congenital modifications of former instincts, perpetuated by the individuals so possess so characterized having been preserved & selected. We must look at every complicated complex instinct one and mechanism in structure & instinct, as the summing up of a long history of contrivances, each most useful to its possessor, much nearly in the same way as when we look at the a great mechanical inventions, as the summing up of repeated the labour, the experience, the reason, & even the blunders of numerous workmen. How interesting does the geographical distribution of all organic bengs, past & present, become, as throwing light on the ancient geography of the world. Geology, on this theory, loses glory from the imperfection of its records archives, but it gains in the immensity immensity of its subject. There is much grandeur in looking at every existing organic being, either as the lineal descendant successor of some form now buried under thousands of feet of solid rock, or as being the co-heir of co-descendant

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with that that buried form of some still more ancient & utterly lost inhabitant of this world. It accords with what we know of the laws impressed by the Creator on matter, that the production & extinction of forms, should, like the birth & death if individuals, be the result of secondary means. It is derogoratory, that the Creator of countless Universes, should have made by individual acts of His will, the myriads of creeping parasites & worms, which since the earliest dawn dawn of life, have swarmed over the land & water in the depths of the sea. ocean. We cease to be astonished, that a group of animals should have been formed to lay their eggs in the bowels & flesh of other sensitive beings,— that some animals should live by, & even delight in cruelty — that animals should be led away away by false instincts,— that annually there should be an incalculable waste of eggs the pollen, eggs & larvæ. of immature beings; for we see in all this the inevitable consequences of one great law of the multiplication of organisms not created immutable. From death, famine & the struggle for existence, we see that the highest good, most exalted end, which we are capable of conceiving, namely the creation of the higher animals,

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has directly proceeded. Doubtless our fir[text excised] impression, is to disbelieve that any secondary law cou[text excised] produce infinitely numerous organisms, organic beings, each characterized by the most exquisite workmanship & widely adaptat extended adaptations: it at first acccords better with our faculties to suppose that each required the fiat of a Creator. There is a simple grandeur in this view of life, with its powers of assimilation & of reproduction, having been originally breathed into matter under a few forms; & that, whilst this planet has gone cycling onwards according to the fixed laws of gravity & land & water form & these [illeg] actions have gone on have continued in endless changes replacing each other,— that from so simple an origin, through this process of gradual selection of infinitesimal varieties changes variations in the first created & successive living beings endowed with life, endless, endless forms most beautiful & most wonderful have been evolved.)