[1v]

First Pencil Sketch of Species Theory

Written at Maer & Shrewsbury during May & June 1842.

(A)

[in pencil in the hand of Francis Darwin:]

This has the same title as Ch 1 of the Bound version

This is a copy or a version of of the beginning of the one in 35 pp which is written in pencil

(1

[in pencil in the hand of Francis Darwin:] Part 1 (p. 1 to 13)

Begin with the most favourable condition for varieties vary at Sect IV

Chapter Part I

On the principles of variation in animal and vegetable organisms under the effects of domesticity

[in pencil in the hand of Francis Darwin:] not in B

The most favourable conditions judging from the results in variation appear to bet Sect.

Sect.

(1). An organism placed under conditions different from those to which it has been adapted by nature, sometimes varies during its individual life in an extremely small degree & in trifling respects; for instance in size, fatness, colour (as birds from peculiar food & certain flowers quality of covering (cats & sheep? transported to hot countries) some habits of mind as tameness & temper. These changes are only sometimes to be distinguished in individual lives & are chiefly to be inferred from what takes place when an organism is exposed for several generations to the proper influences. In individual animals, however, habit seems to effect the body in the development of the muscular system of the whole or of particular parts of the body & together with the circulatory & nervous systems attached to such muscles. Disuse on the other hand causes similar parts to become less & in extreme cases (when from an accident is prevented)

I do not If I might adduce plants because I know of no change except partly in size during same summer & the succeeding flower buds may partly be considered as another individual.

(2

to become atrophied & shrivelled.—

Sect.

(2.) When a individual organism plant is propagated for long periods in domesticity by buds, which is generally considered as a mere extension of the individual, the variation is sometimes greater than happens in the life of an animal individual plant in its strictest sense.

This variation, however, is exceedingly in most cases small, — for instance in the degeneration of the same sort of heartease during succeeding years if badly treated & the improvement & "doubling & singling" "breaking" of tulips from the same bulb when well treated &c.

So marked is this, that constancy is given as a character by florists in their lists.

Sometimes a single bud suddenly assumes a considerably different character, which can be propagated with certainty by budding or grafting &c; for instance, the appearance of moss roses on common roses — of nectarines hereditary on peach-trees - of different coloured chrysanthemums & sweet-williams on same root - of single branch with variegated leaves &c, &c.

There is reason to suppose in some cases for Hybridisation but not in all cases

Sect.

( 3.)

When an organism propagated for many generations in domesticity (as alluded to in Sect. 1) the variation is greater in amount & almost endless in kinds. There seems no part of the body outside or inside which does not vary in some small degree; anatomists dispute what is the "beau ideal" form of the liver, as painters do of the nose or lips. The dispositions, intelligence, and even instincts likewise vary in slight degree (breeds of horses, cattle & dogs & fighting cocks & pigeons). The effects of Habits, which we have stated affect in small degree in organisms.

Explain domesticity V p 3 of this MS in brackets.

(3

(3)

It may be remarked that, from considering the number of organisms which have been domesticated in all times & places endless diversities of country & locality, it seems that the influence of domestication resolves itself into problem conditions different from those under which nature placed the organism, together with these new conditions seldom or never being persistent for very long periods owing to the mutability of the affairs, habits & knowledge of men. In most cases, but not in all may be super added a superabundance of food; & when once several races have been produced (or originally existed in a wild state) the effects produced by crossing them. It may be observed that rearing forest-trees from seed in their native country, in land common soil not highly manured & scarcely differing deserves the term title of domestication; for the seeds in this case are not allowed to sow themselves & struggle against other trees & weeds & so be raised only under the conditions for which nature adapted them. It is improbable

(4

(a

(3)

(4)

The most favourable conditions circumstances for variation seems to be propagation for many generations in domesticity. By domesticity, (Considering the number of organisms which have been domesticated in all times & places; the influence of domesticity seems to resolve itself into conditions different from those under which nature placed the organisms together with their new conditions being seldom or never persistent for centuries together owing to the mutability of the affairs & knowledge of man; in most but not all cases may be superadded a superabundance of food; & occasional crossing the breed with other races. I conclude that this is the case from the vast number of races of organisms which it is known in some cases & may be inferred in others, have probably descended Except probably in domesticity from one parent race source, & from the vast In the few instances, when the cause of variation has been observed, it appears that the new conditions produce but little effect for several generations, & then that as if by an accumulated effect, the original character of the species gives way or "breaks" & numerous varieties are produced. It is probably an analogous result from the accumulated effects of domesticity, which causes the seminal offspring of plants long & highly cultivated by bulbs, slips, buds & grafts by which the individual plant is placed under many conditions to vary in so extraordinary a manner, more than in any animal when there is reason to believe all crossing has been avoided; thus from a simple capsule of a potato seed almost endless varieties have been raised & from a single apple two or more kinds.

[4v]

Variation itself a variable element. whether dependent on conditions or not doubtful.

Perhaps introduce this at back of page 11

(c) The non variation of Peacocks (Turkey not by long introduced) and of asses —freedom of breeding so can it have number of individuals & not precious , so that they  assuredly not be destroyed. — Preciousness does not apply to Donkey = coloured breeds= but these latter are not necessary elements. In many instances. There will be no selection in Peacocks  &c &c except perhaps for white ones & Breeds of such animals, will not be kept in separate countries & treated differently as in case of Pigs &c &c, so that these animals are not selected & are not exposed to different conditions in different countries. —The Peacock, however, is in very different conditions from forests of India —We want facts to know whether it does not vary or whether absence of many breeds. merely owing to non-selection

I suspect the latter. —We must not compare their uniformity with the variability for in these many breeds have been crossed & recrossed

Many trees, from being propagated by slips. keep very uniform.— race to find old breeds of animal plants?

All tends to show importance of selection

Perhaps domestication must be compatible with health?? yet domestic animals unhealthy.—

(4

This tendency to variation is increased no doubt in a great degree by crossing, probably more than by the mere introduction blending of the two parent original stocks forms & this has lead some authors to conclude that variation is confined to cross-bred organisms, but the history of the Potato, the Dahlia, the scotch rose, &c,

[In pencil: the Guinea Pig & Rabbit] will overthrow this notion. The direct effect of certain external conditions, as abundance of food on size & fatness, habits of activity

on the muscular system, & in the periods of maturity & breeding as in birds, cattle, & plants, climate or colour & perhaps nature of covering, and stimulants as wine on certain parts of the body, effect of unknown injurious influence on the body as tendency to goitre, plica polonica, &c, &c, hard roads [two words illeg] treatment on the temper, or tameness, or courage in fighting, or sagacity, habitual peculiar movements, as in paces of horses, - the effects of disuse on the muscular system (as in ducks wings) and or certain qualities of the mind (as in wild rabbits when tamed/ are shown clearly only (as observed in Sect I) when the organisms are bred for several generations under the suitable conditions.

although we must suppose the action comes during the life of each

This fact can only be explained by the slight changes slowly gained by the growth of the growing powers (whether natural or morbid/ of the body & by slight changes in the mind similarly acquired tendency to be transmitted to the offspring, which offspring being similarly exposed goes on acquiring the peculiarity in question; until the full effect which the

(5

external influence tends to can produce, or the life of the organism with permit; is acquired. There is no reason for supposing that changes produced suddenly on the body, as mutilations or lesions from inflammation become hereditary. Endless teeth — as when might be filled — at corresponding ages curious example show that congenital peculiarities (which cannot be attributed to any peculiarity of exposure in parents as extra or defective joints, hairy bodies, &c) tend to appear in the offspring, that are become hereditary. when a peculiarity is not heredetary it wd be called a it is distinctive of a variety where heredetary

(5) Here a distinction in the varieties of organism which I believe is of very great importance, must be pointed out. We have seen that some are produced by the   prolonged effect of external treatment, conditions & habits on the parents, but there are others which spring from the manner in which the reproductive system acts especially under domesticity & which cannot with any probability be attributed as the direct effects of the conditions to which the parents have been exposed. Thus we know that a scope &c more of plants, obviously different from each other have been raised from the same seed-capsule; in this case where both parents draw

[insertion:] & exposed to exactly the same conditions

their nourishment from the same roots in the same flower, it seems impossible to attribute these several varieties directly to external influence, but they must be attributed to the laws of reproduction themselves. We see the same thing but less obviously in the difference of children of same parents, sometimes in twins, and in the same litters of some animals. It will hereafter be shown, that the varieties produced, although not the direct effect of external conditions; seem at least when most plentifully

(6

produced to be the indirect effect, from such changes of external conditions having a more decided effect (independent of state of health) on the reproductive system both in the animal & vegetable kingdoms there or any other part of the body.

(6)

The varieties produced by the direct effects of external conditions & habits & the accidents of the reproductive system are almost endless in kind in number. I state this both from the number of varieties of all odd (& some comparatively new) domesticated organism (leaving out of questions the races of dogs & some other animals which perhaps or probably have descended from several wild stocks) & from the close comparison of individuals of the same race or sub-race. Every part of the external from habits of body & mind seem occasionally to vary in some small degree. Anatomists dispute what is the "beau ideal" form of a liver, as painters do of the nose or lips.

From the (a a) extraordinary number of the varieties of plants produced in the same country & under nearly similar treatment, I conclude, that the differences produced by the accidents of the reproductive system under domesticity are more numerous, then throw away resulting from changes in their form external causes directly effected or successive individuals & accumulated by hereditary transmission in their offspring.—

[6v]

(a a)

Every part of the frame becomes unsettled in a small degree; the reproductive powers under domesticity seem to fail in transmitting such exact likeness as under the natural conditions — the model, as which the young may be said to be cast, varies slightly in every part inside and outside.—

(7

(7) (7)

In crossing races considerably different, as each parent transmits its form, a third race or more will be produced, according to the preponderance of the characters of either parent. Should the parent form be kept pure, the number of races may be thus greatly increased, as soon as two or more are once formed, or if two or more originally existed. There is, moreover, some reason for believing that crossing races gives a great tendency to vary, so that additional races, additional to those produced by the unequal blending of the parent — forms may arise: the production of races by this means (without a careful selection of the intermediate forms) is however, counteracted by the tendency in all varieties, especially in cross-ones breeds to resort to either parent forms — Probably Crossing races is now the most effective means of increasing the number of distinct races. If however the two parent races differ but little and are allowed to cross quite freely so that no pure-bred animals of either parent-breed are left such two races are destroyed & fused together; hence only large numbers of race of the same exist only species of the domesticated animals exist together only in highly civilized & enclosed creations: even want of care for a few years will destroy the case of a much longer period — (compare for instance, the cattle, sheep & horses of S. America with those of Great Britain)

These remarks apply to all all terrestrial animals for all have separate sexes & their races may cross — many plants have & it can be shown that the greater part

(8

and probably perhaps all plants occasionally cross each other. Many aquatic animals have separate sexes, & many of them which have sexes united probably sometimes cross each other.—

The supposed ill-effects of breeding in & in & the good effects of occasionally crossing the breed with individuals of a different family perhaps support the probability that all organisms (which I believe can be deduced from structure) that all most organisms occasionally cross each other, & therefor that races of such organism might cross.—

(8) Experience shows that the readiest way to produce form new races is carefully to watch the occasion many slight varieties been produced by the accidents of the reproductive system under domesticity, & in animals carefully to cross them with the likest forms, or if more such can be found carefully select such of the offspring, as take most after the one selected parent father or mother parent : in most plants it is only necessary to guard against a cross from the pollen of some other individual & to continue selecting. This careful selection & precaution of crossing must be continued for many generations, for though 'like produces like', yet it is found that there

(9

is a constant tendency to vary & especially to revert to the original form. After several generations this tendency lessens & the race become "true" that is it lessens varies less. In all cases the external conditions will & habits of the organism will tend to modify the new race; and then effects may be partly or wholly counteracted, or on the other hand strengthened by selection.

It is wonderful. Agriculturalist & horticulturalists generally often & the latter give their powers of selection wider scope by crossing the races; — It is wonderful that effect which only a few years of selection & without crossing in some cases has produced as many breeds of animals in Great Britain; and yet some of their breeds were very true; so that it would have been thought that little scope was given for selection. Even the most experienced breeders have doubted the probability of that which has [illeg] been affected, when they have compared the offspring new races with the old.

[insertion:] as well then not L Western sheep

This moreover has been done by continued selecting such slight differences in the offspring, that to an unpractised eye would have absolutely undistinguishable. External nature —

Different kinds of selection

trueness

crossing

External condition modify: result of selection

Wonderful effects of selection

(10

under domesticity will adapt the size & form to the amount of food, against which man will in vain struggle — external nature will adapt or influence the colour & in some degree nature of covering to the external will affect especial organs in a singular manner; but by unknown influences, but man will can select by patience races adapted to ends, which can have no influence relates whoever to

on the organism thus will select & therefore in one sense make a race of sheep which cannot climb over walls, will make other races of sheep have long covering & another short & finer —

[insertion:] in the same sense

will make one race adapted to hunt one kind of prey & another a second kind — will make the fat he mixed with the meat in one, beast breed & make it accumulate in the bowels in another for the tallow chandler — will previously determine how the feather on the birds vary. (bautamus & canary [illeg]) shall be coloured, there the legs of one breed of pigeons shall be elongated & the beak in another breed be shortened — shall make the leaves of one breed & the buds of another breed of same plant good to eat at different times of the year &c &c &c.

In saying man makes the breed let it not be confounded with man making the individuals originally possessed given by nature with the desirable qualities in small degree, man only accumulates & adds together & makes a permanent gift of nature's bounty. It would have been an astounding fact if nature had made so many races, many of them adapted to such frivolous ends, & man had only taken advantage of what he found ready made; — but we know such has not been the case.

But in several instances man probably have taken advantage of & adopted breeds produced wholly by the effects of external nature, to his own peculiar ends.—

(11

(11)

(When I have said organisation plastic)

[in margin:] We shall have to discuss period of fœtal existence when varieties supersedes.

Man's power in making breeds is limited independently of the above conditions by the

[insertion:] non or imperfect hereditary

possibility of the variation of the different parts of the organisation, on which he is acting. Some parts vary much more readily than others but it may be doubted whether seems that all parts under domesticity do not occasionally vary in some slight degree.

(loose-hair-loose teeth) (The varieties of different parts are governed by laws in concordance together)

There are probably many unkind laws of variation, dependent as laws of growth;

[insertion:] colour pervades whole system] for instance if one half of the two halves of the body varying together & if the head becomes much elongated, the extremities, it is thought, generally will be so

[insertion:] Crabs bodies & tails  Organic compensation at corresponding periods of age

The most marked tendency in variation, is to return to ancestral forms (20 years)

[insertion:] both were crossed & selected

Even when man meets with the primary variation to select from he must be limited by the health & life of the organism — he has already made progress which feed with difficulty & do not raise their own young. & sheep with so strong a tendency to

[insertion:] Early vegetables) = inflammation (from their tendency to early maturity & powers of fattening) that they cannot live in some localities — he succeeded in making breed a family of oxen with such large hinder quarters till he but was checked by the frequent death of the cows, when bringing forth calves of this structure in this case however, with long time cows might probably have been selected with an inheritable structure would have permitted the birth of calves with this desired structure.

The total amount of variation produced under domestication is quite unknown; for all the most useful animals & many plants have been cultivated so long that their wild source is not known & in many cases there seems reason to believe that the present races have descended from a mixture of wild races, or species, which have inter-bred.

(13

Page 13 ought to come before this

(10) To sum up.

Man makes breeds are made or races 1st by selecting directly exposing organisms by the direct effects to conditions different from those under which they were placed by nature and 2d with greater effect by selecting separately by unknown selection made only professes such dual effect Ch Life of individuals, the varieties, which originate either from the mode of action of the reproductive system, & taking under domesticity or 3d from crossing already established breeds & carefully continuing to select the kind he wants & destroying those which revert to the parent forms & keeping the new breed from crossing with others. After many generations he may in some degree relax his care, the tendency to revert reversion to the parent stock will be diminished

(B)

The Domestication producing variation in the individual offspring, man has to attend only to selection which implies to isolation or the rule if he wants to produce several breeds — by selection alone if there be but a breed he can slowly By these means he can adapt produce infinitely numerous races, most curiously adapted at the same time that the surrounding conditions the capacity for variation, for which, laws of variation modifying his labours. within

Hereafter we will treat as the possible probable amount of variation in different breeds which we can probably man could produce 

whether now or hereafter?

[13v]

B

so that instead of continued selection of a few out of many of the young offspring, he will have only occasionally to remove some one which departs from the new type. And should a cross occasionally take place, its effects will be obvious & easily remedied; & indeed the breed being supposed to be well established such accidental cross-bred animals would (if not selected) be soon blended by repeated crossing & recession into the parent new breed.—