FOOTNOTES:

"The consequences are being now developed of our deplorable ignorance of, or inattention to, one of the most evident traits of natural history—that vegetables, as well as animals, are generally liable to an almost unlimited diversification, regulated by climate, soil, nourishment, and new commixture of already-formed varieties. In those with which man is most intimate, and where his agency in throwing them from their natural locality and disposition has brought out this power of diversification in stronger shades, it has been forced upon his notice, as in man himself, in the dog, horse, cow, sheep, poultry,—in the apple, pear, plum, gooseberry, potato, pea, which sport in infinite varieties, differing considerably in size, colour, taste, firmness of texture, period of growth, almost in every recognizable quality. In all these kinds man is influential in preventing deterioration, by careful selection of the largest or most valuable as breeders."[322]

Étienne and Isidore Geoffroy.

"Both Cuvier and Étienne Geoffroy," says Isidore Geoffroy, "had early perceived the philosophical importance of a question (evolution) which must be admitted as—with that of unity of composition—the greatest in natural history. We find them laying it down in the year 1795 in one of their joint 'Memoirs' (on the Orangs), in the very plainest terms, in the following question, 'Must we see,' they inquire, 'what we commonly call species, as the modified descendants of the same original form?'

"Both were at that time doubtful. Some years afterwards Cuvier not only answered this question in the negative, but declared, and pretended to prove, that the same forms have been perpetuated from the beginning of things. Lamarck, his antagonistpar excellenceon this point, maintained the contrary position with no less distinctness, showing that living beings are unceasingly variable with change of their surroundings, and giving with some boldness a zoological genesis in conformity with this doctrine.

"Geoffroy St. Hilaire had long pondered over this difficult subject. The doctrine which in his old age he so firmly defended, does not seem to have been conceived by him till after he had completed his 'Philosophie Anatomique,' and except through lectures delivered orally to the museum and the faculty, it was not published till 1828; nor again in the work then published do we find his theory in its neatest expression and fullest development."

Isidore Geoffroy St. Hilaire tells us in a note that the work referred to as first putting his father's views before the public in a printed form, was a report to the Academy of Sciences on a memoir by M. Roulin; but that before this report some indications of them are to be found in a paper on the Gavials, published in 1825. Their best rendering, however, and fullest development is in several memoirs, published in succession, between the years 1828 and 1837.

"This doctrine," he continues, "is diametrically opposed to that of Cuvier, and is not entirely the same as Lamarck's. Geoffroy St. Hilaire refutes the one, he restrains and corrects the other. Cuvier, according to him, sums up against the facts, while Lamarck goes further than they will bear him out. Essentially however on questions of this nature he is a follower of Lamarck, and took pleasure on several occasions in describing himself as the disciple of his illustriousconfrère."[323]

I have been unable to detect any substantial difference of opinion between Geoffroy St. Hilaire and Lamarck, except that the first maintained that a line must be drawn somewhere—and did not draw it—while the latter said that no line could be drawn, and therefore drew none. Mr. Darwin is quite correct in saying that Geoffroy St. Hilaire "relied chiefly on the conditions of life, or the 'monde ambiant,' as the cause of change." But this is only Lamarck over again, for though Lamarck attributes variation directly tochange of habits in the creature, he is almost wearisome in his insistence on the fact that the habit will not change, unless the conditions of life also do so. With both writers then it is change in the relative positions of the exterior circumstances, and of the organism, which results in variation, and finally in specific modification.

Here is another sketch of Étienne Geoffroy, also by his son Isidore.

In 1795, while Lamarck was still a believer in immutability, Étienne Geoffroy St. Hilaire "had ventured to say that species might well be 'degenerations from a single type,'" but, though he never lost sight of the question, he waited more than a quarter of a century before passing from meditation to action. "He at length put forward his opinion in 1825, he returned to it, but still briefly, in 1828 and 1829, and did not set himself to develop and establish it till the year 1831—the year following the memorable discussion in the Academy, on the unity of organic composition."[324]

"If," says his son, "he began by paying homage to his illustrious precursor, and by laying it down as a general axiom, that there is no such thing as fixity in nature, and especially in animated nature, he follows this adhesion to the general doctrine of variability by a dissent which goes to the very heart of the matter. And this dissent becomes deeper and deeper in his later works. Not only is Geoffroy St. Hilaire at pains to deny the unlimited extension of variability whichis the foundation of the Lamarckian system, but he moreover and particularly declines to explain those degenerations which he admits as possible, by changes of action and habit on the part of the creature varying—Lamarck's favourite hypothesis, which he laboured to demonstrate without even succeeding in making it appear probable."[325]

Isidore Geoffroy then declares that his father, "though chronologically a follower of Lamarck, should be ranked philosophically as having continued the work of Buffon, to whom all his differences of opinion with Lamarck serve to bring him nearer."[326]If he had understood Buffon he would not have said so.

His conclusions are thus summed up:—"Geoffroy St. Hilaire maintains that species are variable if the environment varies in character; differences, then, more or less considerable according to the power of the modifying causesmay havebeen produced in the course of time, and the living forms of to-daymay bethe descendants of more ancient forms."[327]

It is not easy to see that much weight should be attached to Geoffroy St. Hilaire's opinion. He seems to have been a person of hesitating temperament, under an impression that there was an opening just then through which a judicious trimmer might pass himself in among men of greater power. If his son has described his teaching correctly, it amounts practically to abonâ fideendorsement of what Buffon can only be considered to have pretended to believe. The same objection that must be fatal to the view pretended byBuffon, is so in like manner to those put forward seriously of both the Geoffroys—for Isidore Geoffroy followed his father, but leant a little more openly towards Lamarck. He writes:—

"The characters of species are neither absolutely fixed, as has been maintained by some; nor yet, still more, indefinitely variable as according to others. They are fixed for each species as long as that species continues to reproduce itself in an unchanged environment; but they become modified if the environment changes."[328]

This is all that Lamarck himself would expect, as no one could be more fully aware than M. Geoffroy, who, however, admits that degeneration may extend to generic differences.[329]

I have been unable to find in M. Isidore Geoffroy's work anything like a refutation of Lamarck's contention that the modifications in animals and plants are due to the needs and wishes of the animals and plants themselves; on the contrary, to some extent he countenances this view himself, for he says, "hence arise notable differences of habitation and climate, and these in their turn induce secondary differences in dietand even in habits."[330]From which it must follow, though I cannot find it said expressly, that the author attributes modification in some measure to changed habits, and therefore to the changed desires from which the change of habits has arisen; but in the main he appearsto refer modification to the direct action of a changed environment.

Mr. Herbert Spencer.

"Those who cavalierly reject the theory of Lamarck and his followers as not adequately supported by facts," wrote Mr. Herbert Spencer,[331]"seem quite to forget that their own theory is supported by no facts at all"—inasmuch as no one pretends to have seen an act of direct creation. Mr. Spencer points out that, according to the best authorities, there are some 320,000 species of plants now existing, and about 2,000,000 species of animals, including insects, and that if the extinct forms which have successively appeared and disappeared be added to these, there cannot have existed in all less than some ten million species. "Which," asks Mr. Spencer, "is the most rational theory about these ten millions of species? Is it most likely that there have been ten millions of special creations? or, is it most likely that by continual modificationdue to change of circumstances, ten millions of varieties may have been produced as varieties are being produced still?"

. . . . . . . . . . .

"Even could the supporters of the development hypothesis merely show that the production of species by the process of modification is conceivable, they would be in a better position than their opponents. But they can do much more than this; they can show that the process of modification has effected and is effecting great changes in all organisms, subject tomodifying influences ... they can show that any existing species—animal or vegetable—when placed under conditions different from its previous ones,immediately begins to undergo certain changes of structurefitting it for the new conditions. They can show that in successive generations these changes continue until ultimately the new conditions become the natural ones. They can show that in cultivated plants and domesticated animals, and in the several races of men, these changes have uniformly taken place. They can show that the degrees of difference, so produced, are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show that it is a matter of dispute whether some of these modified formsarevarieties or modified species. They can show too that the changes daily taking place in ourselves; the facility that attends long practice, and the loss of aptitude that begins when practice ceases; the strengthening of passions habitually gratified, and the weakening of those habitually curbed; the development of every faculty, bodily, moral or intellectual, according to the use made of it, are all explicable on this same principle. And thus they can show that throughout all organic nature thereisat work a modifying influence of the kind they assign as the cause of these specific differences, an influence which, though slow in its action, does in time, if the circumstances demand it, produce marked changes; an influence which, to all appearance, would produce in the millions of years, and under the great varieties of condition which geological records imply, any amount of change."

This leaves nothing to be desired. It is Buffon, Dr. Darwin, and Lamarck, well expressed. Those were the days before "Natural Selection" had been discharged into the waters of the evolution controversy, like the secretion of a cuttle fish. Changed circumstances immediately induce changed habits, and hence a changed use of some organs, and disuse of others: as a consequence of this, organs and instincts become changed, "and these changes continue in successive generations, until ultimately the new conditions become the natural ones." This is the whole theory of "development," "evolution," or "descent with modification." Volumes may be written to adduce the details which warrant us in accepting it, and to explain the causes which have brought it about, but I fail to see how anything essential can be added to the theory itself, which is here so well supported by Mr. Spencer, and which is exactly as Lamarck left it. All that remains is to have a clear conception of the oneness of personality between parents and offspring, of the eternity, and latency, of memory, and of the unconsciousness with which habitual actions are repeated, which last point, indeed, Mr. Spencer has himself touched upon.

Mr. Spencer continues—"That by any series of changes a zoophyte should ever become a mammal, seems to those who are not familiar with zoology, and who have not seen how clear becomes the relationship between the simplest and the most complex forms, when all intermediate forms are examined, a very grotesque notion ... they never realize the fact that by small increments of modification, any amount ofmodification may in time be generated. That surprise which they feel on finding one whom they last saw as a boy, grown into a man, becomes incredulity when the degree of change is greater. Nevertheless, abundant instances are at hand of the mode in which we may pass to the most diverse forms by insensible gradations."

Nothing can be more satisfactory and straightforward. I will make one more quotation from this excellent article:—

"But the blindness of those who think it absurd to suppose that complex organic forms may have arisen by successive modifications out of simple ones, becomes astonishing when we remember that complex organic forms are daily being thus produced. A tree differs from a seed immeasurably in every respect—in bulk, in structure, in colour, in form, in specific gravity, in chemical composition—differs so greatly that no visible resemblance of any kind can be pointed out between them. Yet is the one changed in the course of a few years into the other—changed so gradually that at no moment can it be said, 'Now the seed ceases to be, and the tree exists.' What can be more widely contrasted than a newly-born child, and the small, semi-transparent gelatinous spherule constituting the human ovum? The infant is so complex in structure that a cyclopædia is needed to describe its constituent parts. The germinal vesicle is so simple, that a line will contain all that can be said of it. Nevertheless, a few months suffices to develop the one out of the other, and that too by a series of modifications so small, that were theembryo examined at successive minutes, not even a microscope would disclose any sensible changes. That the uneducated and ill-educated should think the hypothesis that all races of beings, man inclusive, may in process of time have been evolved from the simplest monad a ludicrous one is not to be wondered at. But for the physiologist, who knows that every individual beingisso evolved—who knows further that in their earliest condition the germs of all plants and animals whatsoever are so similar, 'that there is no appreciable distinction among them which would enable it to be determined whether a particular molecule is the germ of a conferva or of an oak, of a zoophyte or of a man'[332]—for him to make a difficulty of the matter is inexcusable. Surely, if a single structureless cell may, when subjected to certain influences, become a man in the space of twenty years, there is nothing absurd in the hypothesis that under certain other influences a cell may, in the course of millions of years, give origin to the human race. The two processes are generically the same, and differ only in length and complexity."

The very important extract from Professor Hering's lecture should perhaps have been placed here. The reader will, however, find it on page199.

FOOTNOTES:[321]'Origin of Species,' Hist. Sketch, p. xvi.[322]See 'Naval Timber and Arboriculture,' by Patrick Matthew, published by Adam and C. Black, Edinburgh, and Longmans and Co., London, 1831, pp. 364, 365, 381-388, and also 106-108, 'Gardeners' Chronicle,' April 7, 1860.[323]'Vie et Doctrine Scientifique de Geoffroy Étienne St. Hilaire,' Paris, Strasbourg, 1847, pp. 344-346.[324]'Hist. Nat. Gén.,' tom. ii. 413.[325]'Hist. Nat. Gén.,' tom. ii. p. 415.[326]Ibid.[327]Ibid. p. 421.[328]'Hist. Nat. Gén.,' vol. ii. p. 431, 1859.[329]'Origin of Species,' Hist. Sketch, p. xix.[330]'Hist. Nat. Gén.,' vol. ii. p. 432.[331]See 'The Leader,' March 20, 1852, "The Haythorne Papers."[332]Carpenter's 'Principles of Physiology', 3rd ed., p. 867.

[321]'Origin of Species,' Hist. Sketch, p. xvi.

[322]See 'Naval Timber and Arboriculture,' by Patrick Matthew, published by Adam and C. Black, Edinburgh, and Longmans and Co., London, 1831, pp. 364, 365, 381-388, and also 106-108, 'Gardeners' Chronicle,' April 7, 1860.

[323]'Vie et Doctrine Scientifique de Geoffroy Étienne St. Hilaire,' Paris, Strasbourg, 1847, pp. 344-346.

[324]'Hist. Nat. Gén.,' tom. ii. 413.

[325]'Hist. Nat. Gén.,' tom. ii. p. 415.

[326]Ibid.

[327]Ibid. p. 421.

[328]'Hist. Nat. Gén.,' vol. ii. p. 431, 1859.

[329]'Origin of Species,' Hist. Sketch, p. xix.

[330]'Hist. Nat. Gén.,' vol. ii. p. 432.

[331]See 'The Leader,' March 20, 1852, "The Haythorne Papers."

[332]Carpenter's 'Principles of Physiology', 3rd ed., p. 867.

CHAPTER XIX.

MAIN POINTS OF AGREEMENT AND OF DIFFERENCE BETWEEN THE OLD AND NEW THEORIES OF EVOLUTION.

Having put before the reader with some fulness the theories of the three writers to whom we owe the older or teleological view of evolution, I will now compare that view more closely with the theory of Mr. Darwin and Mr. Wallace, to whom, in spite of my profound difference of opinion with them on the subject of natural selection, I admit with pleasure that I am under deep obligation. For the sake of brevity, I shall take Lamarck as the exponent of the older view, and Mr. Darwin as that of the one now generally accepted.

We have seen, that up to a certain point there is very little difference between Lamarck and Mr. Darwin. Lamarck maintains that animals and plants vary: so does Mr. Darwin. Lamarck maintains that variations having once arisen have a tendency to be transmitted to offspring and accumulated: so does Mr. Darwin. Lamarck maintains that the accumulation of variations, so small, each one of them, that it cannot be, or is not noticed, nevertheless will lead in the course of that almost infinite time during which life has existed upon earth, to very wide differences in form, structure, and instincts: so does Mr. Darwin.Finally, Lamarck declares that all, or nearly all, the differences which we observe between various kinds of animals and plants are due to this exceedingly gradual and imperceptible accumulation, during many successive generations, of variations each one of which was in the outset small: so does Mr. Darwin. But in the above we have a complete statement of the fact of evolution, or descent with modification—wanting nothing, but entire, and incapable of being added to except in detail, and by way of explanation of the causes which have brought the fact about. As regards the general conclusion arrived at, therefore, I am unable to detect any difference of opinion between Lamarck and Mr. Darwin. They are both bent on establishing the theory of evolution in its widest extent.

The late Sir Charles Lyell, in his 'Principles of Geology,' bears me out here. In a note to hisrésuméof the part of the 'Philosophie Zoologique' which bears upon evolution, he writes:—

"I have reprinted in this chapter word for word my abstract of Lamarck's doctrine of transmutation, as drawn up by me in 1832 in the first edition of the 'Principles of Geology.'[333]I have thought it right to do this in justice to Lamarck, in order to show how nearly the opinions taught by him at the commencement of this century resembled those now in vogue amongst a large body of naturalists respecting the infinite variability of species, and the progressive development in past time of the organic world. The readermust bear in mind that when I made this analysis of the 'Philosophie Zoologique' in 1832, I was altogether opposed to the doctrine that the animals and plants now living were the lineal descendants of distinct species, only known to us in a fossil state, and ... so far from exaggerating, I did not do justice to the arguments originally adduced by Lamarck and Geoffroy St. Hilaire, especially those founded on the occurrence of rudimentary organs. There is therefore no room for suspicion that my account of the Lamarckian hypothesis, written by me thirty-five years ago, derived any colouring from my own views tending to bring it more into harmony with the theory since propounded by Darwin."[334]So little difference did Sir Charles Lyell discover between the views of Lamarck and those of his successors.

With the identity, however, of the main proposition which, both Lamarck and Mr. Darwin alike endeavour to establish, the points of agreement between the two writers come to an end. Lamarck's great aim was to discover the cause of those variations whose accumulation results in specific, and finally in generic, differences. Not content with establishing the fact of descent with modification, he, like his predecessors, wishes to explain how it was that the fact came about. He finds its explanation in changed surroundings—that is to say, in changed conditions of existence—as the indirect cause, and in the varying needs arising from these changed conditions as the direct cause.

According to Lamarck, there is a broad principlewhich underlies variation generally, and this principle is the power which all living beings possess of slightly varying their actions in accordance with varying needs, coupled with the fact observable throughout nature that use develops, and disuse enfeebles an organ, and that the effects, whether of use or disuse, become hereditary after many generations.

This resolves itself into the effect of the mutual interaction of mind on body and of body on mind. Thus he writes:—

"The physical and the mental are to start with undoubtedly one and the same thing; this fact is most easily made apparent through study of the organization of the various orders of known animals. From the common source there proceeded certain effects, and these effects, in the outset hardly separated, have in the course of time become so perfectly distinct, that when looked at in their extremest development they appear to have little or nothing in common.

"The effect of the body upon the mind has been already sufficiently recognized; not so that of the mind upon the body itself. The two, one in the outset though they were, interact upon each other more and more the more they present the appearance of having become widely sundered, and it can be shown that each is continually modifying the other and causing it to vary."[335]

And again, later:—

"I shall show that the habits by which we nowrecognize any creature are due to the environment (circonstances) under which it has for a long while existed,and that these habits have had such an influence upon the structure of each individual of the species as to have at length" (that is to say, through many successive slight variations, each due to habit engendered by the wishes of the animal itself), "modified this structure and adapted it to the habits contracted."[336]

These quotations must suffice, for the reader has already had Lamarck's argument sufficiently put before him.

Variation, and consequently modification, are, according to Lamarck, the outward and visible signs of the impressions made upon animals and plants in the course of their long and varied history, each organ chronicling a time during which such and such thoughts and actions dominated the creature, and specific changes being the effect of certain long-continued wishes upon the body, and of certain changed surroundings upon the wishes. Plants and animals are living forms of faith, or faiths of form, whichever the reader pleases.

Mr. Darwin, on the other hand, repeatedly avows ignorance, and profound ignorance, concerning the causes of those variations which, or nothing, must be the fountain-heads of species. Thus he writes of "the complex andlittle knownlaws of variation."[337]"There is alsosome probabilityin the view propounded by Andrew Knight, that variabilitymay be partlyconnected with excess of food."[338]"Many laws regulate variation,somefew of whichcan bedimly seen."[339]"The results of theunknown, orbut dimly understood, laws of variation are infinitely complex and diversified."[340]"We areprofoundly ignorantof the cause of each slight variation or individual difference."[341]"We arefar too ignorantto speculate on the relative importance of the several known and unknown causes of variation."[342]He admits, indeed, the effects of use and disuse to have been important, but how important we have no means of knowing; he also attributes considerable effect to the action of changed conditions of life—but how considerable again we know not; nevertheless, he sees no great principle underlying the variations generally, and tending to make them appear for a length of time together in any definite direction advantageous to the creature itself, but either expressly, as at times, or by implication, as throughout his works, ascribes them to accident or chance.

In other words, he admits his ignorance concerning them, and dwells only on the accumulation of variations the appearance of which for any length of time in any given direction he leaves unaccounted for.

Lamarck, again, having established his principle that sense of need is the main direct cause of variation, and having also established that the variations thus engendered are inherited, so that divergences accumulate and result in species and genera, is comparatively indifferent to further details. His work is avowedly an outline. Nevertheless, we have seen that he wasquite alive to the effects of the geometrical ratio of increase, and of the struggle for existence which thence inevitably follows.

Mr. Darwin, on the other hand, comparatively indifferent to, or at any rate silent concerning the causes of those variations which appeared so all-important to Lamarck, inasmuch as they are the raindrops which unite to form the full stream of modification, goes into very full detail upon natural selection, or the survival of the fittest, and maintains it to have been "the most important but not the exclusive means of modification."[343]

It will be readily seen that, according to Lamarck, the variations which when accumulated amount to specific and generic differences, will have been due to causes which have been mainly of the same kind for long periods together. Conditions of life change for the most part slowly, steadily, and in a set direction; as in the direction of steady, gradual increase or decrease of cold or moisture; of the steady, gradual increase of such and such an enemy, or decrease of such and such a kind of food; of the gradual upheaval or submergence of such and such a continent, and consequent drying up or encroachment of such and such a sea, and so forth. The thoughts of the creature varying will thus have been turned mainly in one direction for long together; and hence the consequent modifications will also be mainly in fixed and definite directions for many successive generations; as in the direction of a warmer or cooler covering; of a better means of defenceor of attack in relation to such and such another species; of a longer neck and longer legs, or of whatever other modification the gradually changing circumstances may be rendering expedient. It is easy to understand the accumulation of slight successive modifications which thus make their appearance in given organs and in a set direction.

With Mr. Darwin, on the contrary, the variations being accidental, and due to no special and uniform cause, will not appear for any length of time in any given direction, nor in any given organ, but will be just as liable to appear in one organ as in another, and may be in one generation in one direction, and in another in another.

In confirmation of the above, and in illustration of the important consequences that will follow according as we adopt the old or the more recent theory, I would quote the following from Mr. Mivart's 'Genesis of Species.'

Shortly before maintaining that two similar structures have often been developed independently of one another, Mr. Mivart points out that if we are dependent upon indefinite variations only, as provided for us by Mr. Darwin, this would be "so improbable as to be practically impossible."[344]The number of possible variations being indefinitely great, "it is therefore an indefinitely great number to one against a similar series of variations occurring and being similarly preserved in any two independent instances." It will be felt (as Mr. Mivart presently insists) that this objection doesnot apply to a system which maintains that in case an animal feels any given want it will gradually develop the structure which shall meet the want—that is to say, if the want be not so great and so sudden as to extinguish the creature to which it has become a necessity. For if there be such a power of self-adaptation as thus supposed, two or more very widely different animals feeling the same kind of want might easily adopt similar means to gratify it, and hence develop eventually a substantially similar structure; just as two men, without any kind of concert, have often hit upon like means of compassing the same ends. Mr. Spencer's theory—so Mr. Mivart tells us—and certainly that of Lamarck, whose disciple Mr. Spencer would appear to be,[345]admits "a certain peculiar, but limited power of response and adaptation in each animal and plant"—to the conditions of their existence. "Such theories," says Mr. Mivart, "have not to contend against the difficulty proposed, and it has been urged that even very complex extremely similar structures have again and again been developed quite independently one of the other, and this because the process has taken place not by merely haphazard, indefinite variations in all directions, but by the concurrence of some other internal natural law or laws co-operating with external influences and with Natural Selection in the evolution of organic forms.

"It must never be forgotten that to admit any such constant operation of any such unknown natural cause is to deny the purely Darwinian theory which relies uponthe survival of the fittest by means of minute fortuitous indefinite variations.

"Among many other obligations which the author has to acknowledge to Professor Huxley, are the pointing out of this very difficulty, and the calling his attention to the striking resemblance between certain teeth of the dog, and of the thylacine, as one instance, and certain ornithic peculiarities of pterodactyles as another."[346]

In brief then, changed distribution of use and disuse in consequence of changed conditions of the environment is with Lamarck the main cause of modification. According to Mr. Darwin natural selection, or the survival of favourable but accidental variations, is the most important means of modification. In a word, with Lamarck the variations are definite; with Mr. Darwin indefinite.

FOOTNOTES:[333]Vol. ii. chap. i.[334]Vol. ii. chap, xxxiv., ed. 1872.[335]'Philosophie Zoologique,' ed. M. Martins, Paris, Lyons, 1873, tom. i. p. 24.[336]'Philosophie Zoologique,' tom. i. p. 72.[337]'Origin of Species,' p. 3.[338]Ibid. p. 5.[339]'Origin of Species,' p. 8.[340]Ibid. p. 9.[341]Ibid. p. 158.[342]Ibid. p. 159.[343]'Origin of Species,' p. 4.[344]'Genesis of Species,' p. 74, 1871.[345]Seeante, p.330, line 1 after heading.[346]'Genesis of Species,' p. 76, ed. 1871.

[333]Vol. ii. chap. i.

[334]Vol. ii. chap, xxxiv., ed. 1872.

[335]'Philosophie Zoologique,' ed. M. Martins, Paris, Lyons, 1873, tom. i. p. 24.

[336]'Philosophie Zoologique,' tom. i. p. 72.

[337]'Origin of Species,' p. 3.

[338]Ibid. p. 5.

[339]'Origin of Species,' p. 8.

[340]Ibid. p. 9.

[341]Ibid. p. 158.

[342]Ibid. p. 159.

[343]'Origin of Species,' p. 4.

[344]'Genesis of Species,' p. 74, 1871.

[345]Seeante, p.330, line 1 after heading.

[346]'Genesis of Species,' p. 76, ed. 1871.

CHAPTER XX.

NATURAL SELECTION CONSIDERED AS A MEANS OF MODIFICATION. THE CONFUSION WHICH THIS EXPRESSION OCCASIONS.

When Mr. Darwin says that natural selection is the most important "means" of modification, I am not sure that I understand what he wishes to imply by the word "means." I do not see how the fact that those animals which are best fitted for the conditions of their existence commonly survive in the struggle for life, can be called in any special sense a "means" of modification.

"Means" is a dangerous word; it slips too easily into "cause." We have seen Mr. Darwin himself say that Buffon did not enter on "thecauses or means"[347]of modification, as though these two words were synonymous, or nearly so. Nevertheless, the use of the word "means" here enables Mr. Darwin to speak of Natural Selection as if it were an active cause (which he constantly does), and yet to avoid expressly maintaining that it is a cause of modification. This, indeed, he has not done in express terms, but he does it by implication when he writes, "Natural Selectionmight be most effective in givingthe proper colour to each kind ofgrouse, and inkeepingthat colour when once acquired." Such language, says the late Mr. G. H. Lewes, "is misleading;" it makes "selection an agent."[348]

It is plain that natural selection cannot be considered a cause of variation; and if not of variation, which is as the rain drop, then not of specific and generic modification, which are as the river; for the variations must make their appearance before they can be selected. Suppose that it is an advantage to a horse to have an especially hard and broad hoof, then a horse born with such a hoof will indeed probably survive in the struggle for existence, but he was not born with the larger and harder hoofbecause of his subsequently surviving. He survived because he was born fit—not, he was born fit because he survived. The variation must arise first and be preserved afterwards.

Mr. Darwin therefore is in the following dilemma. If he does not treat natural selection as a cause of variation, the 'Origin of Species' will turn out to have noraison d'être. It will have professed to have explained to us the manner in which species has originated, but it will have left us in the dark concerning the origin of those variations which, when added together, amount to specific and generic differences. Thus, as I said in 'Life and Habit,' Mr. Darwin will have made us think we know the whole road, in spite of his having almost ostentatiously blindfolded us at every step in the journey. The 'Origin of Species' would thus prove to be no less a piece of intellectual sleight-of-hand than Paley's 'Natural Theology.'

If, on the other hand, Mr. Darwin maintains natural selection to be a cause of variation, this comes to saying that when an animal has varied in an advantageous direction, the fact of its subsequently surviving in the struggle for existence is the cause of its having varied in the advantageous direction—or more simply still—that the fact of its having varied is the cause of its having varied.

And this is what we have already seen Mr. Darwin actually to say, in a passage quoted near the beginning of this present book. When writing of the eye he says, "Variation will cause the slight alterations;"[349]but the "slight alterations"arethe variations; so that Mr. Darwin's words come to this—that "variation will cause the variations."

There does not seem any better way out of this dilemma than that which Mr. Darwin has adopted—namely, to hold out natural selection as "a means" of modification, and thenceforward to treat it as an efficient cause; but at the same time to protest again and again that it is not a cause. Accordingly he writes that "Natural Selectionacts only by the preservation and accumulationof small inherited modifications,"[350]—that is to say, it has had no share in inducing or causing these modifications. Again, "What applies to one animal will apply throughout all time to all animals—that is, if they vary, for otherwise natural selection can effect nothing"[351]; and again, "for natural selection onlytakes advantage of such variations asarise"[352]—the variations themselves arising, as we have just seen, from variation.

Nothing, then, can be clearer from these passages than that natural selection is not a cause of modification; while, on the other hand, nothing can be clearer, from a large number of such passages, as, for instance, "natural selection may beeffectiveingivingandkeepingcolour,"[353]than that natural selection is an efficient cause; and in spite of its being expressly declared to be only a "means" of modification, it will be accepted as cause by the great majority of readers.

Mr. Darwin explains this apparent inconsistency thus:—He maintains that though the advantageous modification itself is fortuitous, or without known cause or principle underlying it, yet its becoming the predominant form of the species in which it appears is due to the fact that those animals which have been advantageously modified commonly survive in times of difficulty, while the unmodified individuals perish: offspring therefore is more frequently left by the favourably modified animal, and thus little by little the whole species will come to inherit the modification. Hence the survival of the fittest becomes a means of modification, though it is no cause of variation.

It will appear more clearly later on how much this amounts to. I will for the present content myself with the following quotation from the late Mr. G. H. Lewes in reference to it. Mr. Lewes writes:—

"Mr. Darwin seems to imply that the external conditions which cause a variation are to be distinguishedfrom the conditions which accumulate and perfect such variation, that is to say, he implies a radical difference between the process of variation and the process of selection. This I have already said does not seem to me acceptable; the selection I conceive to be simply the variation which has survived."[354]

Certainly those animals and plants which are best fitted for their environment, or, as Lamarck calls it, "circonstances"—those animals, in fact, which are best fitted to comply with the conditions of their existence—are most likely to survive and transmit their especial fitness. No one would admit this more readily than Lamarck. This is no theory; it is a commonly observed fact in nature which no one will dispute, but it is not more "a means of modification" than many other commonly observed facts concerning animals.

Why is "the survival of the fittest" more a means of modification than, we will say, the fact that animals live at all, or that they live in successive generations, being born, continuing their species, and dying, instead of living on for ever as one single animal in the common acceptation of the term; or than that they eat and drink?

The heat whereby the water is heated, the water which is turned into steam, the piston on which the steam acts, the driving wheel, &c., &c., are all one as much as another a means whereby a train is made to go from one place to another; it is impossible to say that any one of them is the main means. So (mutatis mutandis) with modification. There is no reason thereforewhy "the survival of the fittest" should claim to be an especial "means of modification" rather than any other necessary adjunct of animal or vegetable life.

I find that the late Mr. G. H. Lewes has insisted on this objection in his 'Physical Basis of Mind.' I observe, also, that in the very passage in which he does so, Mr. Lewes appears to have been misled by Mr. Darwin's use of that dangerous word "means," and, at the same time, by his frequent treatment of natural selection as though it were an active cause; so that Mr. Lewes supposes Mr. Darwin to have fallen into the very error of which, as I have above shown, he is evidently struggling to keep clear—namely, that of maintaining natural selection to be a "cause" of variation. Mr. Lewes then continues:—

"He [Mr. Darwin] separates Natural Selection from all the primary causes of variation either internal or external—either as results of the laws of growth, of the correlations of variation, of use and disuse, &c., and limits it to the slow accumulation of such variations as are profitable in the struggle with competitors. And for his purpose this separation is necessary. But biological philosophy must, I think, regard the distinction as artificial,referring only to one of the great factors in the production of species."[355]

The fact that one in a brood or litter is born fitter for the conditions of its existence than its brothers and sisters, and, again, the causes that have led to this one's having been born fitter—which last is what the olderevolutionists justly dwelt upon as the most interesting consideration in connection with the whole subject—are more noteworthy factors of modification than the factor that an animal, if born fitter for its conditions, will commonly survive longer in the struggle for existence. If the first of these can be explained in such a manner as to be accepted as true, or highly probable, we have a substantial gain to our knowledge. The second is little—if at all—better than a truism. Granted, if it were not generally the case that those forms are most likely to survive which are best fitted for the conditions of their existence, no adaptation of form to conditions of existence could ever have come about. "The survival of the fittest" therefore, or, perhaps better, "the fertility of the fittest," is thus asine quâ nonfor modification. But, as we have just insisted, this does not render "the fertility of the fittest" an especial "means of modification," rather than any othersine quâ nonfor modification.

But, to look at the matter in another light. Mr. Darwin maintains natural selection to be "the most important but not the exclusive means of modification."

For "natural selection" substitute the words "survival of the fittest," which we may do with Mr. Darwin's own consent abundantly given.

To the words "survival of the fittest" add what is elided, but what is, nevertheless, unquestionably as much implied as though it were said openly whenever these words are used, and without which "fittest" has no force—I mean, "for the conditions of their existence."

We thus find that when Mr. Darwin says that naturalselection is the most important, but not exclusive means of modification, he means that the survival in the struggle for existence of those creatures which are best fitted to comply with the conditions of their existence is the most important, but not exclusive means whereby the descendants of a creature, we will say, A, have become modified, so as to be now represented by a creature, we will say, B.

But the word "circonstances," so frequently used by Lamarck for the conditions of an animal's existence, contains, by implication, the idea of animalswhich shall exist or not according as they fulfil those conditions or fail to fulfil them. Conditions of existence are conditions which something capable of existing must fulfil if it would exist at all, and nothing is a condition of an animal's existence which that animal need not comply with and may yet continue to exist. Again, the words "animals" and "plants" comprehend the ideas of "fit," "fitter," and "fittest," "unfit," "unfitter," and "unfittest" for certain conditions, for we know of no animals or plants in which we do not observe degrees of fitness or unfitness for their "circonstances" or environment, or conditions of existence.

The use, therefore, of the term "conditions of existence" is sufficient to show that the person using it intends to imply that those animals and plants will live longest (or survive) and thrive best which are best able to fulfil those conditions. Hence it implies neither more nor less than what is implied by the words "struggle for existence, with consequent survival of the fittest"—that is to say, if we hold the complyingwith any condition of life to which difficulty is attached to be part of "the struggle" for life, and this we should certainly do.

The words "conditions of existence" may, then, be used instead of the "struggle for existence with consequent survival of the fittest," for as they cannot imply any less than the "struggle, &c.," when they are set out in full, and without suppression, so neither do they imply more; for nothing is a condition of existence, in so far as its power of effecting the modification of any animal is concerned, which does not also involve more or less difficulty or struggle; for if there is no difficulty or struggle there will be nothing to bring about change of habit, and hence of structure. This identity of meaning may be also seen if we call to mind that the conditions of existence can be only a synonym for "the conditions of continuing to live," and "the conditions of continuing to live" a synonym for "the conditions of continuing to live a longer time," and "the conditions of continuing to live a longer time," for "the conditions of survival," and "the conditions of survival," for "the survival of the fittest," inasmuch as the being fittest is the condition of being the longest survivor.

But we have already seen that "the survival of the fittest," is, according to Mr. Darwin, a synonym for "natural selection"; hence it follows that "the conditions of existence" imply neither more nor less than what is implied by "natural selection" when this expression is properly explained, and may be used instead of it; so that when Mr. Darwin says that "natural selection" is the main but not exclusive means of modification,he must mean, consciously or unconsciously, that "the conditions of existence" are the main but not exclusive means of modification. But this is only falling in with "the views and erroneous grounds of opinion," as Mr. Darwin briefly calls them, of Lamarck himself; a fact which Mr. Darwin's readers would have seen more readily if he had kept to the use of the words "survival of the fittest" instead of "natural selection." Of that expression Mr. Darwin says[356]that it is "more accurate" than natural selection, but naively adds, "and sometimes equally convenient."

I have said that there is a practical identity of meaning between "natural selection" and "the conditions of existence," when both expressions are fully extended. I say this, however, without prejudice to my right of maintaining that, of the two expressions, the one is accurate, lucid, and calculated to keep the thread of the argument well in sight of the reader, while the other is inaccurate, and always, if I may say so, less "convenient," as being always liable to lead the reader astray. Nor should it be lost sight of that Lamarck and Dr. Erasmus Darwin maintain that species and genera have arisenbecause animals can fashion themselves into accord withtheir conditions, so that, as Lamarck is so continually insisting, the action of the conditions is indirect only—changed use and disuse being the direct causes; while, according to Mr. Darwin, it is natural selection itself (which, as we have seen, is but another way of saying conditions of existence) that is the most important means of modification.

The identity of meaning above insisted on was, on the face of it, almost as obscure as that between "evêqueand bishop." Yet we know that "evêque" is "episc" and "bishop" "piscop," and that "episcopus" is the Latin for bishop; the words, therefore, are really one and the same, in spite of the difference in their appearance. I think I can show, moreover, that Mr. Darwin himself holds natural selection and the conditions of existence to be one and the same thing. For he writes, "in one sense," and it is hard to see any sense but one in what follows, "the conditions of life may be said not only to cause variability" (so that here Mr. Darwin appears to support Lamarck's main thesis) "either directly or indirectly, but likewise to include natural selection; for the conditions determine whether this or that variety shall survive."[357]But later on we find that "the expression of conditions of existence, so often insisted upon by the illustrious Cuvier" (and surely also by the illustrious Lamarck, though he calls them "circonstances") "is fully embraced by the principle of natural selection."[358]So we see that the conditions of life "include" natural selection, and yet the conditions of existence "are fully embraced by" natural selection, which, I take it, is an enigmatic way of saying that they are one and the same thing, for it is not until two bodies absolutely coincide and occupy the same space that the one can be said both to include and to be embraced by the other.

The difficulty, again, of understanding Mr. Darwin's meaning is enhanced by his repeatedly writing of"natural selection," or the fact that the fittest survive in the struggle for existence, as though it were the same thing as "evolution" or the descent, through the accumulation of small modifications in many successive generations, of one species from another and different one. In the concluding and recapitulatory chapter of the 'Origin of Species,' he writes:—

"Turning to geographical distribution, the difficulties encounteredon the theory of descent with modificationare serious enough;"[359]and in the next paragraph, "As, according tothe theory of natural selection, &c.," the context showing that in each case descent with modification is intended.

Again:—

"On the theory of thenatural selectionof successive, slight, but profitable, modifications,"[360]that is to say, on the theory of the survival of the fittest; while on the next page we find "the theory of descent with modification," and "the principle of natural selection," used as though they were convertible terms.

Again:—

"The existence of closely allied or representative species in any two areas implies,on the theory of descent with modification, &c.;"[361]and, in the next paragraph, "the theory of natural selection, with its contingencies of extinction and divergence of character," is substituted as though the two expressions were identical.

This is calculated to mislead. Independently of the fact that "natural selection," or "the survival of thefittest," is in no sense a theory, but simply an observed fact, yet even if the words are allowed to stand for "descent with modification by means of natural selection," it is still misleading to write as though this were synonymous with "the theory of evolution," or "the theory of descent with modification." To do this prevents the reader from bearing in mind that "evolution by means of the circumstance-suiting power of plants and animals" as advanced by the earlier evolutionists; and "evolution by means of lucky accidents" with comparatively little circumstance-suiting power, are two very different things, of which the one may be true and the other untrue. It leads the reader to forget that evolution by no means stands or falls with evolution by means of natural selection, and makes him think that if he accepts evolution at all, he is bound to Mr. Darwin's view of it. Hence, when he falls in with such writers as Professor Mivart and the Rev. J. J. Murphy, who show, and very plainly, that the survival of the fittest, unsupplemented by something which shall give a definite aim to the variations which successively occur, fails to account for the coadaptations of need and structure, he imagines that evolution has much less to say for itself than it really has. If Mr. Darwin, instead of taking the line which he has thought fit to adopt towards Buffon, Dr. Erasmus Darwin, Lamarck, and the author of the 'Vestiges,' had shown us what these men taught, why they taught it, wherein they were wrong, and how he proposed to set them right, he would have taken a course at once more agreeable with ordinary practice, and more likelyto clear misconception from his own mind and from those of his readers.

Mr. Darwin says,[362]"it is easy to hide our ignorance under such expressions as 'the plan of creation' and 'unity of design.'" Surely, also, it is easy to hide want of precision of thought, and the absence of any fundamental difference between his own main conclusion and that of Dr. Darwin and Lamarck whom he condemns, under the term "natural selection."

I assure the reader that I find the task of forming a clear, well-defined conception of Mr. Darwin's meaning, as expressed in his 'Origin of Species,' comparable only to that of one who has to act on the advice of a lawyer who has obscured the main issue as far as he can, and whose chief aim has been to make as many loopholes as possible for himself to escape through in case of his being called to account. Or, again, to that of one who has to construe an Act of Parliament which was originally framed so as to throw dust in the eyes of those who would oppose the measure, and which, having been since found unworkable, has had clauses repealed and inserted up and down it, till it is in an inextricable tangle of confusion and contradiction.

As an example of my meaning, I will quote a passage to which I called attention in 'Life and Habit.' It runs:—

"In the earlier editions of this work I underrated, as now seems probable, the frequency and importance of modifications due to spontaneous variability. But it is impossible to attribute tothis cause" (i. e. spontaneousvariability, which is itself only an expression for unknown causes) "the innumerable structures which are so well adapted to the habits of life of each species. I can no more believe inthis" (i. e. that the innumerable structures, &c., can be due to unknown causes) "than that the well adapted form of a racehorse or greyhound, which, before the principle of selection by man was well understood, excited so much surprise in the minds of the older naturalists, canthus" (i. e. by attributing them to unknown causes) "be explained."[363]

This amounts to saying that unknown causes can do so much, but cannot do so much more. On this passage I wrote, in 'Life and Habit':—

"It is impossible to believe that, after years of reflection upon his subject, Mr. Darwin should have written as above, especially in such a place, if his mind was clear about his own position. Immediately after the admission of a certain amount of miscalculation there comes a more or less exculpatory sentence, which sounds so right that ninety-nine people out of a hundred would walk through it, unless led by some exigency of their own position to examine it closely, but which yet, upon examination, proves to be as nearly meaningless as a sentence can be."[364]

No one, to my knowledge, has impugned the justice of this criticism, and I may say that further study of Mr. Darwin's works has only strengthened my conviction of the confusion and inaccuracy of thought, which detracts so greatly from their value.

So little is it generally understood that "evolution" and what is called "Darwinism" convey indeed the same main conclusion, but that this conclusion has been reached by two distinct roads, one of which is impregnable, while the other has already fallen into the hands of the enemy, that in the last November number of the 'Nineteenth Century' Professor Tyndall, while referring to descent with modification or evolution, speaks of it as though it were one and inseparable from Mr. Darwin's theory that it has come about mainly by means of natural selection. He writes:—

"Darwin's theory, as pointed out nine or ten years ago by Helmholtz and Hooker, was then exactly in this condition of growth; and had they to speak of the subject to-day they would be able to announce an enormous strengthening of the theoretic fibre. Fissures in continuity which then existed, and which left little hope of being ever spanned, have been since bridged over, so that the furtherthe theoryis tested the more fully does it harmonize with progressive experience and discovery. We shall never probably fill all the gaps; but this will not prevent a profound belief in the truth ofthe theoryfrom taking root in the general mind. Much less will it justify a total denial ofthe theory. The man of science, who assumes in such a case the position of a denier, is sure to be stranded and isolated."

This is in the true vein of the professional and orthodox scientist; of that new orthodoxy which is clamouring for endowment, and which would step into the Pope's shoes to-morrow, if we would only let it. IfProfessor Tyndall means that those who deny evolution will find themselves presently in a very small minority, I agree with him; but if he means that evolution is Mr. Darwin's theory, and that he who rejects what Mr. Darwin calls "the theory of natural selection" will find himself stranded, his assertion will pass muster with those only who know little of the history and literature of evolution.

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