RECORD: Anon. 1868. Darwin and pangenesis. Quarterly Journal of Science 5 (July): 295-313.
REVISION HISTORY: Transcribed (single key) by AEL Data, corrections by John van Wyhe 9.2010. RN1
I. DARWIN AND PANGENESIS.
IT is nearly ten years since the most important work on biological science which has ever been published, namely, the 'Origin of Species,' issued from the press; and during the long interval, interrupted, we regret to say, by bodily illness, the well-known author of that work has been accumulating further evidence in favour of his theory, which he now gives to the world. So far, his detailed information relates almost entirely to animals and plants under domestication;* and although the work in which it is contained forms a continuation of the argument in favour of the derivative origin of species, it does not conclude the consideration of the subject; and we are promised, first, a work upon the variability of organic beings in a state of nature; secondly, one upon the difficulties opposed to the theory of natural selection; and, finally, one in which it is apparently intended by the author to give a résumé of the whole subject, and wherein he will "try the principle of natural selection, by seeing how far it will give a fair explanation of the several classes of facts alluded to."† We confess that these announcements have taken us a little by surprise; for seeing that the esteemed author of these works, extant and promised, is already about sixty years of age, and that ten years have elapsed between the appearance of his introductory treatise and the one now before us, which is by no means the most important of the series, he must have sufficient faith in his own theory of the "survival of the fittest" to anticipate the extension of his brilliant career to at least the age of ninety. All we can say is, that we hope his expectations may be realized, and that the accumulation of knowledge and thought in the meantime may enable
* 'The Variation of Animals and Plants under Domestication.' By Charles Darwin, M.A., F.R.S., &c. In two vols., with illustrations. Murray, 1868.
† Ibid., vol. i., p. 9.
VOL. V. Y
him to bequeath to mankind a biological theory which shall bear the test of future ages, and firmly secure the pedestal of fame upon which the reputation of its author is already elevated.
It may be within the memory of some of our readers, that about six years after the appearance of the 'Origin of Species'—when, therefore, sufficient time had elapsed to enable all classes of thinkers to express their views upon the Darwinian theory—we ventured to review the state of scientific opinion upon the subject, and to add such original thoughts as that review had suggested to us;* and as we find in the work before us many attempts to explain difficulties which at that time appeared to us to militate against the unqualified acceptance of the Darwinian doctrine, we may be pardoned for once more touching upon them, with a view to consider whether those obstacles have been removed in the present work, or whether they still impart to the hypothesis an imperfection which needs to be supplied before it can be converted into a well-acknowledged biological guide for all ages.
It appeared to us at that time, as it has to many others, that the author claimed for what he terms "natural selection," powers to modify old species as well as render permanent the character of new ones,—thus implying intelligence and every other attribute requisite for that purpose; and we sought to show that the author himself had not formed a clear conception of what "natural selection" is able to accomplish. We quoted one of his remarks, that "it" (natural selection) "can modify the egg, seed, or young, as easily as the adult;"† but endeavoured to show, by collateral quotations, that the author rather considered the "conditions of life" as the causes which induce variability, and that then "natural selection" accumulates those variations when they are profitable for the animal. Now, as by "natural selection" the author meant the part played by nature (the conditions of existence by which the living form is surrounded) analogous to man's operations in selecting and training animals under domestication; so, just as we might say of any change in the nature of an animal, "fattening" or "crossing" has effected it, instead of "the breeder has effected it by fattening or crossing;" we must not be too nice in our distinction of terms, and we must regard "Nature," the "conditions of existence," "natural selection," as in so far one and the same great power favouring the continued existence of certain types, and even in some degree modifying those types, just as the breeder modifies his domesticated animals. But even granting to the author the utmost licence in the use of terms, we could not then, and cannot now, help being drawn insensibly to the conclusion that the departure from any existing type results in the
* "Darwin and his Teachings:" 'Quarterly Journal of Science,' April, 1866.
† 'Origin of Species,' 3rd edition (1861), p. 144, par. 2.
main from a change in the reproductive organs of the animal; and it appears to us that whilst in his earlier work the author laid too little stress upon this obscure phase of his subject, it has haunted him throughout the present work; and though he still attributes to the external conditions of existence the chief influence in modifying species (or even varieties), we find his expressions much more clear concerning the agency which immediately operates to bring about this modification, for he says:—"The causes which induce variability act on the mature organism, on the embryo, and, as we have good reason to believe, on both sexual elements before impregnation has been effected."*
Now this is what may be called a much clearer declaration of principle than we have hitherto had from the author; and, leaving out of sight the question of the amount of variability which can by any means be brought about, we find that virtually, according to his views, the nature of the living form is decided at its very conception. For, whether the most widely diverging characters have been secured, as in the author's favourite illustration, the pigeon, or some "spontaneous" variation has sprung up, or some peculiarity has been lost sight of for one or more generations and has suddenly reappeared, in every case, and especially in the latter, the reproductive elements, or one of them, must, according to the author's views, have been the acting or perpetuating agency. In order to account for this marvellous property of the germ, the author has supplied us with a provisional hypothesis, "pangenesis," and has sought to explain how the sexual elements operate upon the fabric of which they serve as the basis. But there still remains a wide subject untouched; and that is, whether and in what degree the reproductive organs are affected by certain psychical causes, with which neither "conditions of existence" nor yet "natural selection" have any immediate relation.
This phase of the question must, however, be left for a moment unconsidered; and having referred to the crucial difficulty upon which we stumble when we regard the mode in which variation begins, we must next touch upon that other perplexing problem, hybridism, which is considered by the author's opponents to denote its limits, and to stand as an insuperable obstacle in the way of the acceptance of his theory. In our former notice of the author's works referred to above, we ventured to express the view that the phenomenon of hybridism should be regarded in the light of an occasional check placed by Providence upon the too rapid tendency to vary, which might arise even under the author's slow process, and might cause a reversion to the original stock, or a confusion of forms, totally subversive of all order in animated
* 'Animals and Plants under Domestication,' vol. ii., p. 270.
nature; and although such a view may be seized upon by the opponents of the theory as an admission that there is a limit to variation, and that therefore no new species can thus have been brought into existence (a corollary which by no means results from our proposition), yet we find that in the work before us the author quite concurs with our views, excepting that he seeks to explain how hybridism is affected by nature, whilst we contented ourselves with suggesting that Providence does bring about such results, without as yet seeing clearly by what means they are effected. He first compares the phenomena relating to this subject in domesticated animals with those in a state of nature:—"On the principle which makes it necessary for man, whilst he is selecting and improving his domestic varieties, to keep them separate, it would clearly be advantageous to varieties in a state of nature, that is, to incipient species, if they could be kept from blending, either through sexual aversion or by becoming mutually sterile. Hence it at one time appeared to me probable, as it has to others, that this sterility might have been acquired through natural selection. On this point we must suppose that a shade of lessened fertility first spontaneously appeared, like any other modification, in certain individuals of a species when crossed with other individuals of the same species, and that successive degrees of infertility, from being advantageous, were slowly accumulated."*
The words italicized by us show that the author had thus only removed the difficulty a little farther from view than before, but he has now come to the conclusion that "species have not been rendered mutually infertile through the accumulative action of natural selection;" … "that they have not been endowed through an act of creation with this quality;" but that "it has arisen incidentally during their slow formation in connection with other and unknown changes in their organization."† The word (again underlined by us) would lead one to think that the difficulty remains to the author pretty much where it was; but the context shows that he attributes the changes in the reproductive system leading to hybridism to a correlative variation in the whole living form, that is, that when the whole fabric changes, that portion of it which perpetuates the animal changes also, and the ultimate agency is again "pangenesis;" but then again he says, "Pangenesis does not throw much light on hybridism."‡
There is another view taken by the author, of the occurrence and effect of hybridism in nature, which deserves mention. He finds that when wild animals are at first domesticated, the sudden change in the surrounding conditions of their life renders them for a time infertile: "numerous facts," he says, "have been given,
* 'Animals and Plants under Domestication,' vol. ii., p. 185.
† Ibid., p. 188.
‡ Ibid., p. 385.
showing that when animals are first subjected to captivity, even in their native land, and although allowed much liberty, their reproductive functions are often greatly impaired or quite annulled;"* but, on the other hand, crosses between varieties slightly modified render the offspring rather more fertile than otherwise. Now he believes that what occurs under domestication by a leap, is slowly proceeding in nature; for natura non facit saltum, and that infertility has been gradually proceeding from changed conditions of existence, extending over long ages, but resulting at length in as marked a difference as when the conditions have been suddenly changed from freedom to captivity.
But here, again, whilst the author's results appear to be correctly stated, the parallel by which he seeks to explain the cause is unfortunate and inapplicable; for in the case of domestication a male and female of the same variety (or one of them) are suddenly rendered quite infertile, their "fertility becomes at once quite annulled;" whereas in nature the individuals of the same species remain quite fertile, inter se, whilst it is only when they come to be crossed with other species that the union is barren.
But there is still another aspect of the question, in which a simple statement of facts alone gives to the theory of modification a large amount of weight.
In seeking to show that the barrier of hybridism is not so formidable as his antagonists would make it appear, the author says:
"The sterility of distinct species when first united, and that of their hybrid offspring, graduates by an almost infinite number of steps, from zero, when the ovule is never impregnated and a seed capsule is never formed, up to complete fertility. We can only escape the conclusion that some species are fully fertile when crossed, by determining to designate as varieties all the forms which are quite fertile. This high degree of fertility is, however, rare. Nevertheless, plants which have been exposed to unnatural conditions sometimes become modified in so peculiar a manner that they are much more fertile when crossed by a distinct species than when fertilized by their own pollen. Success in effecting a first union between species and the fertility of their hybrids depends in an eminent degree on the conditions of life being favourable. The innate sterility of hybrids of the same parentage and raised from the same seed-capsule often differs much in degree."†
In our notice of the author's former work we charged him with making light of the difficulties of hybridism. The fact is, he was already in possession of a mass of information which justified his giving less weight to that phase of the question than we were disposed to do, for, in common with many other critics, we had been
* 'Animals and Plants under Domestication,' vol. ii., p. 176
† Ibid., p. 179.
taught to believe that "species" means two distinct types whose union is infertile. But whatever may be urged against the author's speculations upon the causes of certain natural phenomena, no one who knows anything of his character as an observer and writer will receive his statements of facts otherwise than with the most implicit confidence.
And now in regard to this apparently insurmountable difficulty of hybridism, the author tells us that, as a rule, "species," that is, widely diverging types, are infertile with each other, but that there are not only cases where they are fertile, but as we descend in the scale of nature, the crossing of species under certain conditions actually increases fertility, and that the only escape from making this admission in many cases, is by reasoning in a circle and calling species varieties because they are fertile. Well, as we do believe the author's statements of facts, and as we consider the terms "variety," "species," "genus," &c, to have been introduced into natural history by man for the guidance of his own limited intellect, and to have no actual existence in nature, we are unable to find any rational objection to the broad principle laid down by the author and his predecessors holding similar views, that all new forms of life are and have been modified descendants of pre-existing ones. Nor have we ever been able to see any other rational mode of accounting for the progression of nature. It is, indeed, quite proper at all times that new philosophical theories should be received with "philosophical caution;" it is perfectly just that persons who hold opinions which have been accepted as truths in the past, should require of those who desire to convert them to a new philosophical faith, a large amount of trustworthy evidence in its favour, and should insist upon the clearing away of patent obstacles to its acceptance; but, adopting one of the ordinary principles of jurisprudence, when such an amount of evidence has been advanced, and when obstacles which were previously deemed insurmountable have been shown not to be so, the onus of proof then falls upon those who have held the original faith, which may have been conceived in ignorance, and perpetuated by unreasoning philosophical conservatism.
The facts contained in the work before us already show that great modifications in osteological and external structure, and great divergences in habit, may in a brief period be brought about by the changed conditions and artificial selection practised under domestication. These modifications are so great, that were it not for the fertility of the varieties when crossed, no naturalist would hesitate to class them as distinct species. It is also proved almost to a certainty that many domesticated "breeds" which are fertile when intercrossed have descended from ancestors of different species.
Again, a glance at the history of the past shows us that step by
step new and more completely organized forms have been superseding old and (in one sense) less perfect ones. Where links have been missing one day, they have been discovered the next. Gaps which appeared insurmountable are constantly being bridged over by the discovery of organic remains, notwithstanding that a great portion of these are still concealed from human research. The growth of the individual is completely typical of what the advocates of descent by modification maintain to have been the history of animated nature.
All these facts are strongly in favour of the theory of the formation of new species by modified descent, and what evidence have the advocates of the opposite theory to advance in its favour? Indeed, it is difficult to find out what their theory really is, or rather what their theories are, for it would hardly be possible to find half-a-dozen anti-Darwinians who, if they think at all, think alike.
Leaving out of the question the means by which the modifications have been brought about, but not doubting for an instant that it has been by slow gradation and natural agencies, and without any derangement of the laws of nature as generally accepted by mankind, we conceive that at least sufficient valid evidence has now been laid before the scientific world to justify its acceptance, pure and simple, of the law of descent by modification, from the operation of which law there is no reason whatever to exclude Man; and all unbiassed thinkers will now expect from the opponents of that theory that they will desist from attacking the new and rational doctrine with absurd theological denunciations, or with quibbles concerning the precise nature of the zoological term "species," but that they will put forward a clear defence of some definite doctrine of their own; will explain with ordinary clearness how they believe new types really have been introduced, and will support their defence by well-established scientific data.
We all know how easy and convenient it is to dash off an article upon such a work as the one before us, in which the world is informed in two or three columns of pompous common-places, that the reviewer sees no new proof of the author's theory, and that until such proofs are forthcoming, it must continue to be regarded as "purely hypothetical;" in other words, that persons who have no inclination to believe it, may reject it until the critic does see some convincing proof of its validity; and of course it is much easier, and, in a reviewing sense, pays much better to make such an announcement a week after the volumes have appeared (which have employed ten years of the author's life), than if the criticism be reserved for even a fortnight's perusal and consideration. It is equally facile, in these days of free-thought, for a person whose biological doctrines have been imbibed from the first chapter of Genesis, and some elementary work on Natural History, to
triumph over an unfortunate "Darwinian" by daring him to admit that he believes a Christian and a bull to have had the same ancestry!
But with the exception of a few thinking observers—the measure of whose information is only exceeded by their caution, which prevents them from accepting the new theory—the large majority of its opponents are really such reasoners as we have described; and it appears to us that the acceptance of the theory will depend more upon the decline of superstition than upon the ascendancy of knowledge.
To return, however, to our difficulties. Another feature in the theory of modification of species which presents evidence for as well as against the doctrine of "natural selection" is the inheritance of peculiarities.
In his 'Origin of Species'* the author said:—"The laws governing inheritance are quite unknown: no one can say why a peculiarity in different individuals of the same species, or in individuals of different species, is sometimes inherited and sometimes not so, why the child often reverts in certain characters to its grandfather or grandmother, or more remote ancestor." But as we stated in our criticism already referred to, this very ignorance of the causes of inheritance presents a grave obstacle to acceptance of the doctrine of modification through the external conditions of life; for what can that power have effected "where the deceased father is resembled by a posthumous child?"† Had such inherited peculiarities been mental only, they might have resulted from early training; but if we take a case which is not unusual, that the grandchild by a daughter of the grandfather resembles the latter both in features and character, then we have the mental and physical peculiarities of a male transmitted through two females, the mother and daughter.
The mode in which we sought to explain such a wonderful phenomenon, and one, as it appeared to us, then at variance with the author's views, was that "from the very commencement of life up to the present hour there are evidences of an immediate designing power"—or, to use a term which is looked upon with disfavour by many Darwinians, an ordaining power—an occult influence in the production and modification of the sexual elements, and consequently of the beings springing from them, totally distinct from the "conditions of existence," "natural selection," or whatever the force may be called which influences the embryo and the born creature.‡ The justification we have for quoting these few expressions of our own, is that to a large extent the author seems to have
* P. 13, 8th edition.
† "Darwin and his Teachings:" 'Journal of Science,' vol. iii., p. 174.
‡ Ibid., p. 174.
adopted the suggestions we then made; and he seeks now to show what that "occult influence" is which modifies the male and female elements of reproduction. Without losing his hold upon the "conditions of existence" which, as we have shown, he considers to be one of the main causes of change in the organs of reproduction, he finds in "pangenesis" the solution of the problem and the immediate means by which the change is effected.
And now for his provisional hypothesis of "pangenesis." To explain it in his own words, it "implies that the whole organization in the sense of every atom or unit reproduces itself. Hence ovules and pollen-grains—the fertilized seed or egg, as well as buds—include and consist of a multitude of germs thrown off from each separate atom of the organism."
In short, it is the application of the atomic theory to living forms; is in perfect conformity with all the teachings of correlation between vital and physical forces, and as a provisional hypothesis, is well worthy of the consideration which the author and others have bestowed upon it.*
The author believes (at least as far as we can judge from his remarks on such an obscure subject) that all changes in the various organisms which result from the contact of the spermatozoon and ovum, as well as those which are derived from gemmation or budding, have their origin in the nature of the cells which constitute the elements or materials in operation. The cells or units which constitute all living bodies, from the simplest to the most complex, are themselves organized, and consist of lesser cells or atoms having various natures, and according to the author they give off those constituent atoms as "gemmules," and the nature of those atoms or "gemmules" fixes the future character of the organism into which they enter.
In this manner he seeks to account for the first variation in living types; for the transmission of inherited peculiarities from a grandfather, say, through a daughter to a grandchild; for hybridism. Let us endeavour to explain briefly and as popularly as possible, how the author believes that pangenesis acts in these cases. It must be presumed, first, that the male and female elements each contain a due proportion of cells composed of "gemmules." If there is a preponderance of certain gemmules in the paternal element of reproduction over those of the female, then the offspring may either resemble the father in the next generation, or the effect, being one of quantity, may be latent in that generation and only appear in the succeeding one—the peculiarity being transmitted through the reproductive organs of the intermediate generation which showed no such peculiarity. If the preponderance (the
* An able article on the subject, called "Cell Life," by Dr. Fick, of Zurich, will be found in this Journal, April, 1866.
"prepotency," as he terms it) be with the mother or female parent, then her or, if a plant, its likeness will be transmitted.
Now, if we once admit, what is of course quite a matter of speculation, namely, that the male and female elements are built up of atoms possessing different properties, bone-forming atoms, flesh-forming atoms, fat-forming atoms, to speak popularly, it is natural to suppose that these atoms when they are distributed through the organism may have an attraction for their kind, and this the author also assumes, and as a consequence that if there be a variation in the constitution of the reproductive elements, there will be a tendency to vary in the whole organism, and thus new varieties may arise.
But, finally, if one or both of the sexual elements should be deficient in those gemmules, or in the kind of gemmules necessary for fertilization of some particular form, so that one or both, instead of being "prepotent," should be "impotent," then hybridity is the result—that is, the male of one may be impotent with the female of another species, or vice versâ; or they may be mutually infertile.
Some of our readers will probably have felt a little difficulty in following us through this intricate "provisional hypothesis," for it removes still farther from the reach of our senses the agencies by which vital changes are supposed by the author to be brought about in animated nature. That naturalists will have to devote their attention to this obscure question is, however, quite certain; but the large majority of readers, even those tolerably well acquainted with biological phenomena, will only see in the "provisional hypothesis" a means of solving a difficult problem by another still more difficult of solution.
First, let us confine ourselves to the physical aspect of the question. Perhaps the simplest form of cell known to us is the Amœba. This consists of cell-contents probably enclosed in a highly elastic cell-wall. The cell-contents comprise a nucleus or germ, a nucleolus within the nucleus, and a number of granules floating in a semi-fluid substance often called "sarcode." This simple cell is already believed to possess in its nucleus and nucleolus some kind of organs of reproduction; but according to the author, it must contain a vast number of gemmules of different natures, for it is from such cells as these, in all probability, that many higher organisms have been built up. It does not necessarily follow that such a cell should contain "gemmules" of all kinds needful for the assimilation of the various organic and inorganic substances with which higher organisms that will proceed from it "by descent" are to be nourished; but what the cell must at some time or other have (according to the author's views) is a tendency to vary, else we should come to a standstill at the very threshold of "nature's progression," and all the beautiful varieties
of infusoria, even, would have remained still in the conception of the Maker.
Now what perplexes us is, how in this humble form the surrounding conditions of external nature can operate to bring about a "tendency to vary." To say that we are unable to understand this, and the less therefore we say about it the better—as the author occasionally does when he comes to a dead-lock in some mystery of nature—is taking refuge behind even less defensible breastworks than those of his opponents; for they have at least a Divine force and Will to appeal to on all such occasions. The author says, at the conclusion of his chapter on "pangenesis:"—"Finally, the power of propagation possessed by each separate cell, using the term in its largest sense, determines the reproduction, the variability, the development, and renovation of each living organism." (But, we would ask parenthetically, how does that cell itself begin to vary?) "No other attempt has been made, imperfect as this confessedly is, to connect under one point of view these several grand classes of facts. We cannot fathom the marvellous complexity of an organic being; but, on the hypothesis here advanced, this complexity is much increased. Each living creature must be looked at as a microcosm—a little universe formed of a host of self-propagating organisms, inconceivably minute, and as numerous as the stars in the heaven."
In regard to the latter portion of this paragraph, we cordially award to the able author the credit of having exhibited and illustrated the theory of cell-life, in a manner so novel and interesting as to take it out of the mere province of speculation, and to present it as one well deserving of the earnest consideration of biologists. The application of its principles to the phenomena of the hereditary transmission of peculiarities, whether they be normal or abnormal, such as the inheritance of peculiar features or of special diseases, opens out a wide field for research, and ere long the physical aspect of many of those phenomena may be made clear; but when he treats living "gemmules" as he would atoms of inorganic matter which go to form crystals, and seeks to clear up the difficulties accompanying the first tendency to vary by resorting to this almost unconsidered theory to account for the defects in his own well-founded hypothesis, we have an exhibition of weakness rather than an addition of strength.
Just let us examine one or two of his examples of the operation of pangenesis.
The author finds that when animals are suddenly brought under domestication, they are for a time infertile, and, as it has already been shown, this infertility is compared with that which gradually supervenes as varieties become more divergent in Nature.
Now, it is quite possible that in both these cases the number of
the hypothetical "gemmules" in the spermatozoon or ovule may be deficient or their nature defective; but has it yet been shown that in the instance first named there is any spermatozoon at all in existence? Would it not be more philosophical to ascertain first whether the material element is present or absent (we of course refer to the higher animals, in which the phenomenon of hybridism comes out most prominently) before we attempt to discuss the number or nature of its constituents, of which we at present know nothing?
Or in these same cases of hybridism induced by sudden captivity, or by divergence in nature, we would ask the author, Are the periodical movements and the affinities of the sexual elements already so well understood that it should be safe to pass them by and descend to the consideration of the probable effect of their hypothetical invisible constituents?
But, on the other hand, there can be no doubt that when the male and female elements are perfect and perform their proper functions, they do possess powers which exceed in strangeness anything that the most fertile imagination has yet invented. Just imagine a man with a finger wanting on one hand, and one or more of his children being born with the same defect! It is just within the range of possibility that the state of mind of the mother may by some mysterious influence have caused that defect to be reproduced; but looking at all similar phenomena, it is far more probable that the defect has been communicated by the paternal male element to the ovum, and thus perpetuated in the embryo.
Let us now, however, turn for a moment to the psychical phenomena which present themselves when we consider the tendency of living types to vary, and the occasional checks which are put upon their divergence, and we shall find the cell-theory as little able to account for those as we should find a musical instrument capable of conveying an explanation of the passions which, its notes inspire in the human breast, and which nerve the arm of the warrior, exhausted by a weary march, or lull to rest the spirit of a fretful child.
The author, as we have seen, admits that the reproductive elements constitute that portion of the organism in or through which the tendency to vary probably first manifests itself, but (if we understand him correctly) he attributes the change in those elements to altered physical conditions alone. Now, if we pass in review before our mind's eye the various types of animals which must have succeeded each other through modified descent, we find that amongst the lower forms it is just possible to conceive that the tendency to variation in the reproductive elements might be the result of external physical influences alone; but this admission would of itself be fatal to the application of the same theory to
the higher animals, whose tendency to vary (we do not speak of any special organs) depends palpably to a large extent upon the action of mental influences. An Actinia may find itself surrounded by natural conditions over which it has no control, as changed food, deficiency or superabundance of light, or any other physical cause, and which may bring about a change in its reproductive elements, and thus give rise to a new variety. But would it be either natural or rational to apply this rule to the higher animals, especially to Man? Is it not certain that there we have psychical forces inducing actions, and those actions bringing about new varieties, and in a manner independently of those material influences which operate lower down in the animal scale.
A union may be brought about between two human beings solely from the attractions of the mind; and let us suppose some marked mental quality to be inherited. Now, we are apt to use the term "inherited" somewhat arbitrarily; for what appears to be thus communicated might, after all, be the result of mental training or example, which would have operated in a foster-child as well as in true offspring, and in that case the illustration would cease to hold good. But assuming that there is a "prepotency" on the side of the father to transmit his likeness, and that therefore some slight cerebral characteristic descends to the son, upon whom training and example are brought to bear, so that the mental quality, whatever it may be, comes to be developed in a higher degree in the son than in the father.
Here we have two distinct states of facts and two forces: the one physical, the other psychical; the one material, and explicable only upon a "provisional hypothesis," the other metaphysical, and yet as clear and patent as any such matters can be to the human mind.
In the parents, love or respect operating, it is true, through the senses, but uninfluenced by the "sense" in a lower acceptation of the term, brings about a union which is to lead to a new variation both in the physical and psychical nature of man. In the offspring, solicitude evinced in training or teaching, that is, mental intercommunication, and later on the unfettered will of the offspring, develop and perpetuate the mental quality, and almost certainly mould the brain and physical frame in conformity to the new condition: the immaterial, impalpable soul acts, invisibly to us, upon the brain, just as we develop the muscles through physical exercise; but prominent before all other phenomena we find the will, the soul, the active, guiding, moving force at work, and at work upon willing, passive materials.
Now look at the materialistic hypothesis. We will admit that it is possible a "prepotency" in the father may have given his likeness to the son: that the supposed order, number, nature, and
disposition of the supposed gemmules in the male organ may have been the first cause of this transmission. We admit that surrounding physical conditions, such as like food, climate, and habits, may have had some share in moulding the physical frame as it became developed. We will even, for argument's sake, admit the cellular hypothesis in its most materialistic form, and suppose that the little, hypothetical, invisible, vitalized atoms are themselves the seat of all those qualities which accumulate as they (the atoms) accumulate; and that they are the motive power instead of the mere instruments upon which the psychical forces act. But are not these very admissions,—does not this very process of reasoning, with all its hypotheses and its uncertainties, sink back into ridiculous improbability before the clear, unmistakable operation of the psychical forces upon the subservient vegetative system—a system complex, indeed, as the author declares it to be, but complex only in the same sense as a musical instrument is so whilst it stands silently and unconsciously awaiting the touch of the master-hand, impelled by the master-spirit?
Nor is the comparison between Nature and Art in this case so entirely figurative as it would appear at first sight. The musical instrument has no power of growth, but the most we can say of nature, or "Natural Selection," in moulding man, is that it is the unconscious agent, like the artizan who collects and selects the materials and builds them up, little dreaming of the heavenly music which will be extracted from them. Then comes the skilful tuner, Man, who, under the tuition of his Creator, brings the mental chords into harmony; and finally the freed Soul, acting independently, wakes the fabric into active life, as the inspired musician wakes the mute instrument into melodious strains; but, in every case, in nature as in art, who doubts that an intelligent designing Mind is in constant operation?
That the author doubts the constant interposition of a designing Mind in nature is clear from his concluding remarks; and in order to render him justice, we will extract those remarks in full, for it will be seen how thoroughly ungenerous, or how utterly ignorant are those who brand his theory as Atheistical, and him as an Atheist, whilst at the same time it will exhibit the feebleness of that reasoning which has led him and some few of his disciples to disbelieve in the immediate and constant interposition of Providence in the development of the universe.
"Some authors have declared that Natural Selection explains nothing, unless the precise cause of each individual difference be made clear. Now, if it were explained to a savage utterly ignorant of the art of building, how the edifice had been raised stone upon stone, and why wedge-formed fragments were used for the arches, flat
stones for the roofs, &c.; and if the use of each part and of the whole building were pointed out, it would be unreasonable if he declared that nothing had been made clear to him, because the precise cause of the shape of each fragment could not be given. But this is a nearly parallel case with the objection that selection explains nothing because we know not the cause of each individual difference in the structure of each being.
"The shape of the fragments of stone at the base of our precipice may be called accidental, but this is not strictly correct; for the shape of each depends on a long sequence of events, all obeying natural laws; on the nature of the rock, on the lines of deposition or cleavage, on the form of the mountain, which depends on its upheaval and subsequent denudation, and lastly on the storm or earthquake which threw down the fragments. But in regard to the use to which the fragments may be put, their shape may be strictly said to be accidental. And here we are led to face a great difficulty, in alluding to which I am aware that I am travelling beyond my proper province. An omniscient Creator must have foreseen every consequence which results from the laws imposed by Him. But can it be reasonably maintained that the Creator intentionally ordered, if we use the words in an ordinary sense, that certain fragments of rock should assume certain shapes so that the builder might erect his edifice? If the various laws which have determined the shape of each fragment were not predetermined for the builder's sake, can it with any greater probability be maintained that He specially ordained for the sake of the breeder each of the innumerable variations in our domestic animals and plants;—many of these variations being of no service to man, and not beneficial—far more often injurious—to the creatures themselves? Did He ordain that the crop and tail-feathers of the pigeon should vary in order that the fancier might make his grotesque pouter and fantail breeds? Did He cause the frame and mental qualities of the dog to vary in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man's brutal sport? But if we give up the principle in one case,—if we do not admit that the variations of the primeval dog were intentionally guided, in order that the greyhound, for instance, that perfect image of symmetry and vigour, might be formed,—no shadow of reason can be assigned for the belief that variations alike in nature and the result of the same general laws, which have been the groundwork through natural selection of the formation of the most perfectly adapted animals in the world, man included, were intentionally and specially guided. However much we may wish it, we can hardly follow Professor Asa Gray in his belief that 'variation has been led along certain beneficial lines,' like a stream 'along definite and useful lines of irrigation.' If we assume that
each particular variation was from the beginning of all time preordained, the plasticity of organization, which leads to many injurious deviations of structure, as well as that redundant power of reproduction which inevitably leads to a struggle for existence, and as a consequence to the natural selection or survival of the fittest, must appear to us superfluous laws of nature. On the other hand, an omnipotent and omniscient Creator ordains everything and foresees everything. Thus we are brought face to face with a difficulty as insoluble as is that of free-will and predestination."*
Here we have an illustrated confession of faith (if it can be so called), which is well deserving of consideration.
Truly, those who say that "natural selection" explains nothing, because the author of the theory does not attempt to "make clear the precise cause of each individual difference," are unreasonable; but were we to accept the simile of the temple built of stones which have fallen from the heights, "natural selection" would avail nothing for the author of the 'Origin of Species.' If, conforming to his wish expressed here, but certainly not elsewhere in his works, we simply accept the law of selection as accounting for the uses to which the stones have been applied in the building of the temple, what have we gained in knowledge of the causes or forces which led to the shape of the stones? In other words, "natural selection" has been in operation for the purpose of preserving the fittest varieties, whether new "species" arose through modified descent or whether they were special creations. All the author shows by his simile is that an intelligent mind has selected and preserved the most fitting varieties or types, as the builder selected the stones best adapted for his purpose, a proposition which, we need hardly tell our readers, we are quite prepared to admit. But the author is not satisfied with attributing to physical causes the selection and retention of fitting types; he tries to find in those causes alone the springs of variation.†
And, to pass on now to the remaining portion of the paragraphs which we have extracted: he believes furthermore that, popularly and generally speaking, all those variations have been accidental, and not pre-ordained; although, in conclusion, he confesses that the omnipotence and omniscience of the Creator "ordains everything and foresees everything;" and so the author does not exactly know what to believe. But his grounds for not believing that variations were pre-ordained and pre-designed, if we may use the term, are the strangest we have ever read.
"Do you imagine," he says, "that God made the wild dog plastic
* 'Animals and Plants under Domestication,' vol. ii., pp. 430–2.
† See 'Animals and Plants under Domestication,' chap. xxii. (especially the Summary on "Causes of Variability," and the whole chapter on "Pangenesis").
and variable in its nature, that man might select and perpetuate a ferocious type to pander to his cruel taste of bull-fighting?"
"Certainly not," is supposed to be our answer.
"Then," says the author triumphantly, "you must at the same time admit that this plasticity and law of natural selection could not have been pre-ordained for the purpose of producing the most symmetrical and perfect of dogs, the greyhound; and now, if the law did not contemplate the formation of the ugly and useless, nor yet that of the symmetrical and vigorous, it could not have contemplated anything at all, and all the results found in nature are accidental, so to speak!"
Does the author forget that Man has a free-will and the power to control nature as well as God? and that in his folly, fancy, or caprice, he often misapplies materials and misdirects natural forces for his own selfish ends? And are we on that account to close our eyes to every manifestation of design, arrangement, and coordination which presents itself in nature, and to say that the abuse shall explain the use, the exception shall constitute the rule? Shall we measure God's wisdom by our folly? His knowledge by our ignorance?
But the author has sufficiently pointed out elsewhere in his work, that "nature" has modified living types with purposes widely different from those of man, namely, for the benefit of the creature itself. "What does the breeder care," he says,* "about any slight change in the molar teeth of his pigs, or for an additional molar tooth in the dog, or for any change in the intestinal canal, or other internal organ? The breeder cares for the flesh of his cattle being well marbled with fat, and for an accumulation of fat within the abdomen of his sheep, and this he has effected." "Natural species, on the other hand, have been modified exclusively for their own good, to fit them for infinitely diversified conditions of life," &c.†
What would the author say if we adopted his method of reasoning thus:—"The plasticity of the ox was not designed with a view to its being fattened for man's use: this application was an accidental one. In like manner, and with still greater force, it may be added that the refuse of oil seeds, known as cattle-cake, has been accidentally applied to the fattening of the ox, for the husk and exhausted tissue were designed for a different purpose." And so the whole scheme of Providence would vanish, and natural forces, divinely and designedly guided, would give place to a beautiful, well-regulated, co-ordinated chapter of accidents!!
All he proves by his reasoning is that whilst our knowledge and power over nature are limited, those of God are unlimited; that whilst God operates for the benefit of all his living creatures,
* See 'Animals and Plants under Domestication,' p. 412.
† Ibid., p. 413.
VOL. V. Z
we are too apt to apply our power and knowledge to selfish purposes; and in all probability that, whilst our powers of modifying varieties so as to form new species are limited by restricted information and the brief duration of life, those of the Almighty know no such bounds. Nature is his handiwork; natural forces are his servants; and to Him there is no time, but an eternal "now" for the execution of his wise and infinitely varied schemes.
The author's illustration of the temple built by human hands out of the rough stones of nature, is susceptible of another application besides the one he has given to it. The explanation of the mode in which the stones have been selected is not to be found in the atoms of which they are constituted, nor on the physical forces which have given them their imperfect forms. They have to be made perfect for the end designed, by the intelligently guided hand of the artizan, and to be raised up into a useful and ornamental structure upon the pre-existing plan of the designing architect.
But whilst we are unable to agree with the author in his views as to the first causes of variability, and the operation of that mysterious influence which binds us to nature, and both to God; and whilst we feel that it is for the interest of scientific truth, after which no man seeks more earnestly than the author himself, that we should exhibit the fallacy and unhesitatingly express our disapproval of the line of argument which he adopts in these speculative matters, still we find in the mass of evidence already advanced by him, both designedly, with a view to establish his theory, and unconsciously in his descriptions of natural phenomena, such ample proofs of the production of new species by modified descent, that we are surprised any thinking person should still adhere to a doctrine which has only theological prejudices and long-established ignorance to support it. And as to the provisional hypothesis of "pangenesis," it is theoretically and materially consistent with all else that has been recently ascertained in other departments of physical science. Those who have studied natural phenomena with the aid of the microscope must have been satisfied that what we have been in the habit of calling the lowest forms of life are not so in reality; and coupling the appearances revealed by that instrument with the facts disclosed in the animated discussions which have from time to time taken place on the so-called "spontaneous generation," we see in "pangenesis" a probable solution of the difficulty.
But on the other hand, whether these supposed vital atoms vary in their constitution, or whether, resembling each other, they have yet varied powers of assimilating inorganic substances, is a secret which neither the indefatigable and all-observant author, nor any one else, can at present decide; and we must await the perfection of our instruments before we are able even to hazard an opinion in
that respect. And furthermore, instead of enabling us to dispense with the theory of an immediate, constant, and designing Providence, this minute subdivision of vitality, so to speak, adds, in our humble opinion, to the necessity for a still more immediate and constant association between the invisible Spirit and his visible Universe. We can conceive of Man being entrusted with powers of selecting small differences, and by wise adaptation creating new types; we can conceive of " influencing the plastic forms of the lower animals, and causing the fittest to survive; but when we descend to cells and gemmules, the very atoms which constitute the unconscious elements of reproduction, we can conceive of no force except the Prime Force which shall determine their nature and operations, and decide what great results shall spring from such insignificant causes.
Of the author's rare merits as an observer; of his undeviating adherence to the truth so far as he can perceive it, and at whatever cost to his feelings; of his bold avowal of his tenets, without regarding the spirit in which they are likely to be received by a half-educated and theologically-prejudiced public, it is unnecessary for us to speak; his works answer for themselves.
Darwin stands side by side with Galileo; he is not only figuratively, but actually, as great a philosopher. Happily in our day retractations can no longer be enforced; and no such mental or bodily sacrifices to the cause of truth are required now as formerly. There may be thousands who, reading by proxy or thinking by substitute, would like to see him incarcerated for blasphemy; but there are myriads of intelligent men, lay as well as clerical, who look forward anxiously to each new revelation of his mind and pen, and love and admire the bold pioneer of truth as though they were his intimate friends and associates. But though Darwin has once more told the world that Nature moves, as Galileo proclaimed that the earth moves, yet he has only partially discovered the secret of its motion; and judging from the persistency with which he seeks in nature only the causes of nature's change (a feeling resulting no doubt from too close observation of details), we believe it is left for some other eye to see the apple fall, and solve the great mystery of vital gravitation. Some day the mind will no doubt visit us which can grasp the whole range of vital phenomena, and at a glance comprehend the action of those mysterious forces which cause physical atoms of like constitution to seek each other amid varying external conditions; the opening flower to follow the sun in its course; which produce the wonderful affinity between the unconscious elements of reproduction; which lead the bird to seek its mate; the weaker mind to lean upon the stronger; the soul to search for, to expand, and to change its own nature by association with its God.
WILLIAM CROOKES, F.R.S.
With Illustrations on Copper, Wood, and Stone.
JOHN CHURCHILL AND SONS, NEW BURLINGTON STREET.
VICTOR MASSON ET FILS.
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Citation: John van Wyhe, editor. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
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