Evolution, Old & New Part 7

"What author," he asks, "has ever p.r.o.nounced more decidedly than Buffon in favour of the invariability of species? Where can we find a more decided expression of opinion than the following?

"'The different species of animals are separated from one another by a s.p.a.ce which Nature cannot overstep.'"

On turning, however, to Buffon himself, I find the pa.s.sage to stand as follows:--

"_Although_ the different species of animals are separated from one another by a s.p.a.ce which Nature cannot overstep--_yet some of them approach so nearly to one another in so many respects that there is only room enough left for the getting in of a line of separation between them_,"[57] and on the following page he distinctly encourages the idea of the mutability of species in the following pa.s.sage:--

"In place of regarding the a.s.s as a degenerate horse, there would be more reason in calling the horse a more perfect kind of a.s.s (un ane perfectionne), and the sheep a more delicate kind of goat, that we have tended, perfected, and propagated for our use, and that the more perfect animals in general--especially the domestic animals--_draw their origin from some less perfect species of that kind of wild animal which they most resemble. Nature alone not being able to do as much as Nature and man can do in concert with one another_."[58]

But Buffon had long ago declared that if the horse and the a.s.s could be considered as being blood relations there was no stopping short of the admission that all animals might also be blood relations--that is to say, descended from common ancestors--and now he tells us that the a.s.s and horse _are_ in all probability descended from common ancestors. Will a reader of any literary experience hold that so laborious, and yet so witty a writer, and one so studious of artistic effect, could ignore the broad lines he had laid down for himself, or forget how what he had said would bear on subsequent pa.s.sages, and subsequent pa.s.sages on it? A less painstaking author than Buffon may yet be trusted to remember his own work well enough to avoid such literary bad workmanship as this. If Buffon had seen reason to change his mind he would have said so, and would have contradicted the inference he had originally p.r.o.nounced to be deducible from an admission of kinship between the a.s.s and the horse.

This, it is hardly necessary to say, he never does, though he frequently thinks it well to remind his reader of the fact that the a.s.s and the horse are in all probability closely related. This is bringing two and two together with sufficient closeness for all practical purposes.

Should not M. Geoffroy's question, then, have rather been "Who has ever p.r.o.nounced more grudgingly, even in an early volume, &c., &c., and who has more completely neutralized whatever concession he might appear to have been making?"

Nor does the only other pa.s.sage which M. Geoffroy brings forward to prove that Buffon was originally a believer in the fixity of species bear him out much better. It is to be found on the opening page of a brief introduction to the wild animals. M. Geoffroy quotes it thus: "We shall see Nature dictating her laws, so simple yet so unchangeable, and imprinting her own immutable characters upon every species." But M.

Geoffroy does not give the pa.s.sage which, on the same page, admits mutability among domesticated animals, in the case of which he declares we find Nature "rarement perfectionnee, souvent alteree, defiguree;" nor yet does he deem it necessary to show that the context proves that this unchangeableness of wild animals is only relative; and this he should certainly have done, for two pages later on Buffon speaks of the American tigers, lions, and panthers as being "degenerated, if their original nature was cruel and ferocious; or, rather, they have experienced the effect of climate, and under a milder sky have a.s.sumed a milder nature, their excesses have become moderated, and by the changes which they have undergone they have become more in conformity with the country they inhabit."[59]

And again:--

"If we consider each species in the different climates which it inhabits, we shall find perceptible varieties as regards size and form: they all derive an impress to a greater or less extent from the climate in which they live. _These changes are only made slowly and imperceptibly._ Nature's great workman is Time. He marches ever with an even pace, and does nothing by leaps and bounds, but by degrees, gradations, and succession he does all things; and the changes which he works--at first imperceptible--become little by little perceptible, and show themselves eventually in results about which there can be no mistake.

"Nevertheless animals in a free, wild state are perhaps less subject than any other living beings, man not excepted, to alterations, changes, and variations of all kinds. Being free to choose their own food and climate, they vary less than domestic animals vary."[60] The conditions of their existence, in fact, remaining practically constant, the animals are no less constant themselves.

The writer of the above could hardly be claimed as a very thick and thin partisan of immutability, even though he had not shown from the first how clearly he saw that there was no middle position between the denial of all mutability, and the admission that in the course of sufficient time any conceivable amount of mutability is possible. I will give a considerable part of what I have found in the first six volumes of Buffon to bear one way or the other on his views concerning the mutability of species; and I think the reader, so far from agreeing with M. Isidore Geoffroy that Buffon began his work with a belief in the fixity of species, will find, that from the very first chapter onward, he leant strongly to mutability, even if he did not openly avow his belief in it.

In support of this a.s.sertion, one quotation must suffice:--

"Nature advances by gradations which pa.s.s unnoticed. She pa.s.ses from one species, and often from one genus to another by imperceptible degrees, so that we meet with a great number of mean species and objects of such doubtful characters that we know not where to place them."[61]

The reader who turns to Buffon himself will find the idea that Buffon took a less advanced position in his old age than he had taken in middle life is also without foundation.

Mr. Darwin has said that Buffon "does not enter into the causes or means of the transformation of species." It is not easy to admit the justice of this. Independently of his frequently insisting on the effect of all kinds of changed surroundings, he has devoted a long chapter of over sixty quarto pages to this very subject; it is to be found in his fourteenth volume, and is headed "De la Degeneration des Animaux," of which words "On descent with modification" will be hardly more than a literal translation. I shall give a fuller but still too brief outline of the chapter later on, and will confine myself here to saying that the three princ.i.p.al causes of modification which Buffon brings forward are changes of climate, of food, and the effects of domestication. He may be said to have attributed variation to the direct and specific action of changed conditions of life, and to have had but little conception of the view which he was himself to suggest to Dr. Erasmus Darwin, and through him to Lamarck.

Isidore Geoffroy, writing of Lamarck, and comparing his position with that taken by Buffon, says, on the whole truly, that "what Buffon ascribes to the general effects of climate, Lamarck maintains to be caused, especially in the case of animals, by the force of habits; _so that, according to him, they are not, properly speaking, modified by the conditions of their existence, but are only induced by these conditions to set about modifying themselves_."[62] But it is very hard to say how much Buffon saw and how much he did not see. He may be trusted to have seen that if he once allowed the thin end of this wedge into his system, he could no more a.s.sign limits to the effect which living forms might produce upon their own organisms by effort and ingenuity in the course of long time, than he could set limits to what he had called the power of Nature if he was once to admit that an a.s.s and a horse might, through that power, have been descended from a common ancestor. Nevertheless, he shows no unwillingness or recalcitrancy about letting the wedge enter, for he speaks of domestication as inducing modifications "sufficiently profound to become constant and hereditary in successive generations ...

_by its action on bodily habits it influences also their natures, instincts, and most inward qualities_."[63]

This is a very thick thin end to have been allowed to slip in unawares; but it is astonishing how little Buffon can see when he likes. I hardly doubt but he would have been well enough pleased to have let the wedge enter still farther, but this fluctuating writer had a.s.signed himself his limits some years before, and meant adhering to them. Again, in this very chapter on Degeneration, to which M. Geoffroy has referred, there are pa.s.sages on the callosities on a camel's knees, on the llama, and on the haunches of pouched monkeys which might have been written by Dr.

Darwin himself.[64] They will appear more fully presently. Buffon now probably felt that he had said enough, and that others might be trusted to carry the principle farther when the time was riper for its enforcement.

FOOTNOTES:

[51] 'Origin of Species,' p. xiii. ed. 1876.

[52] 'Hist. Nat. Gen.,' tom. ii. p. 405, 1859.

[53] 'Origin of Species,' p. xiv. 1876.

[54] 'Hist. Nat. Gen.,' tom. ii. p. 383.

[55] Tom. iv.

[56] 'Hist. Nat. Gen.,' tom. ii. p. 391, 1859.

[57] Tom. v. p. 59, 1755.

[58] Tom. v. p. 60.

[59] Tom. vi. p. 58, 1756.

[60] Tom. vi. pp. 59-60, 1756.

[61] Tom. i. p. 13, 1749.

[62] 'Hist. Nat. Gen.,' tom. ii. p. 411, 1859.

[63] Tom. xi. p. 290, 1764 (misprinted on t.i.tle-page 1754).

[64] See tom. xiv. p. 326, 1766; and p. 162 of this volume.

CHAPTER XI.

BUFFON--FULLER QUOTATIONS.

Let us now proceed to those fuller quotations which may answer the double purpose of bearing me out in the view of Buffon's work which I have taken in the foregoing pages, and of inducing the reader to turn to Buffon himself.

I have already said that from the very commencement of his work Buffon showed a proclivity towards considerations which were certain to lead him to a theory of evolution, even though he had not, as I believe he had, already taken a more comprehensive view of the subject than he thought fit to proclaim unreservedly.

In 1749, at the beginning of his first volume he writes:--

"The first truth that makes itself apparent on serious study of Nature, is one that man may perhaps find humiliating; it is this--that he, too, must take his place in the ranks of animals, being, as he is, an animal in every material point. It is possible also that the instinct of the lower animals will strike him as more unerring, and their industry more marvellous than his own. Then, running his eye over the different objects of which the universe is composed, he will observe with astonishment that we can descend by almost imperceptible degrees from the most perfect creature to the most formless matter--from the most highly organized animal to the most entirely inorganic substance. He will recognize this gradation as the great work of Nature; and he will observe it not only as regards size and form, but also in respect of movements, and in the successive generations of every species.[65]

"Hence," he continues, "arises the difficulty of arriving at any perfect system or method in dealing either with Nature as a whole or even with any single one of her subdivisions. The gradations are so subtle that we are often obliged to make arbitrary divisions. Nature knows nothing about our cla.s.sifications, and does not choose to lend herself to them without reserve. We therefore see a number of intermediate species and objects which it is very hard to cla.s.sify, and which of necessity derange our system whatever it may be."[66]

"The attempt to form perfect systems has led to such disastrous results that it is now more easy to learn botany than the terminology which has been adopted as its language."[67]

After saying that "_la marche de la Nature_" has been misunderstood, and that her progress has ever been by a succession of slow steps, he maintains that the only proper course is to cla.s.s together whatever objects resemble one another, and to separate those which are unlike. If individual specimens are absolutely alike, or differ so little that the differences can hardly be perceived, they must be cla.s.sed as of the same species; if the differences begin to be perceptible, but if at the same time there is more resemblance than difference, the individuals presenting these features should be cla.s.sed as of a different species, but as of the same genus; if the differences are still more marked, but nevertheless do not exceed the resemblances, then they must be taken as not only specific but generic, though as not sufficient to warrant the individuals in which they appear, being placed in different cla.s.ses. If they are still greater, then the individuals are not even of the same cla.s.s; but it should be always understood that the resemblances and differences are to be considered in reference to the entirety of the plant or animal, and not in reference to any particular part only.[68] The two rocks which are equally to be avoided are, on the one hand, absence of method, and, on the other, a tendency to over-systematize.[69]

Like Dr. Erasmus Darwin, and more recently Mr. Francis Darwin, Buffon is more struck with the resemblances than with the differences between animals and plants, but he supposes the vegetable kingdom to be a continuation of the animal, extending lower down the scale, instead of holding as Dr. Darwin did, that animals and vegetables have been contemporaneous in their degeneration from a common stock.

"We see," he writes, "that there is no absolute and essential difference between animals and vegetables, but that Nature descends by subtle gradations from what we deem the most perfect animal to one which is less so, and again from this to the vegetable. The fresh-water polypus may perhaps be considered as the lowest animal, and as at the same time the highest plant."[70]

Looking to the resemblances between animals and plants, he declares that their modes of reproduction and growth involve such close a.n.a.logy that no difference of an essential nature can be admitted between them.[71]

On the other hand, Buffon appears, at first sight, to be more struck with the points of difference between the mental powers of the lower animals and man than with those which they present in common. It is impossible, however, to accept this as Buffon's real opinion, on the strength of isolated pa.s.sages, and in face of a large number of others which point stealthily but irresistibly to an exactly opposite conclusion. We find pa.s.sages which show a clear apprehension of facts that the world is only now beginning to consider established, followed by others which no man who has kept a dog or cat will be inclined to agree with. I think I have already explained this sufficiently by referring it to the impossibility of his taking any other course under the circ.u.mstances of his own position and the times in which he lived.

Buffon does not deal with such pregnant facts, as, for example, the geometrical ratio of increase, in such manner as to suggest that he was only half aware of their importance and bearing. On the contrary, in the very middle of those pa.s.sages which, if taken literally, should most shake confidence in his judgment, there comes a sustaining sentence, so quiet that it shall pa.s.s unnoticed by all who are not attentive listeners, yet so encouraging to those who are taking pains to understand their author that their interest is revived at once.