(Boston, 1877, p. 11); also the present writer in his _Text-book of Zoology_ (1878).
CHAPTER XIII
THE EVOLUTIONARY VIEWS OF BUFFON AND OF GEOFFROY ST. HILAIRE
Of the French precursors of Lamarck there were four--Duret (1609), De Maillet (1748), Robinet (1768), and Buffon. The opinions of the first three could hardly be taken seriously, as they were crude and fantastic, though involving the idea of descent. The suggestions and hypotheses of Buffon and of Erasmus Darwin were of quite a different order, and deserve careful consideration.
[Ill.u.s.tration: MAISON DE BUFFON, IN WHICH LAMARCK LIVED, 1793-1829]
George Louis Leclerc, Comte de Buffon, was born in 1707 at Montbard, Burgundy, in the same year as Linne. He died at Paris in 1788, at the age of eighty-one years. He inherited a large property from his father, who was a councillor of the parliament of Burgundy. He studied at Dijon, and travelled abroad. Buffon was rich, but, greatly to his credit, devoted all his life to the care of the Royal Garden and to writing his works, being a most prolific author. He was not an observer, not even a closet naturalist. "I have pa.s.sed," he is reported to have said, "fifty years at my desk." Appointed in 1739, when he was thirty-two years old, Intendant of the Royal Garden, he divided his time between his retreat at Montbard and Paris, spending four months in Paris and the remainder of the year at Montbard, away from the distractions and dissipations of the capital. It is significant that he wrote his great _Histoire naturelle_ at Montbard and not at Paris, where were the collections of natural history.
His biographer, Flourens, says: "What dominates in the character of Buffon is elevation, force, the love of greatness and glory; he loved magnificence in everything. His fine figure, his majestic air, seemed to have some relation with the greatness of his genius; and nature had refused him none of those qualities which could attract the attention of mankind.
"Nothing is better known than the _navete_ of his self-esteem; he admired himself with perfect honesty, frankly, but good-naturedly."
He was once asked how many great men he could really mention; he answered: "Five--Newton, Bacon, Leibnitz, Montesquieu, and myself." His admirable style gained him immediate reputation and glory throughout the world of letters. His famous epigram, "_Le style est l"homme meme_" is familiar to every one. That his moral courage was scarcely of a high order is proved by his little affair with the theologians of the Sorbonne. Buffon was not of the stuff of which martyrs are made.
His forte was that of a brilliant writer and most industrious compiler, a popularizer of science. He was at times a bold thinker; but his prudence, not to say timidity, in presenting in his ironical way his thoughts on the origin of things, is annoying, for we do not always understand what Buffon did really believe about the mutability or the fixity of species, as too plain speaking in the days he wrote often led to persecution and personal hazard.[125]
His cosmological ideas were based on those of Burnet and Leibnitz. His geological notions were founded on the labors of Palissy, Steno, Woodward, and Whiston. He depended upon his friend Daubenton for anatomical facts, and on Gueneau de Montbeliard and the Abbe Bexon for his zoological data. As Flourens says, "Buffon was not exactly an observer: others observed and discovered for him. He discovered, himself, the observations of others; he sought for ideas, others sought facts for him." How fulsome his eulogists were is seen in the case of Flourens, who capped the climax in exclaiming, "Buffon is Leibnitz with the eloquence of Plato;" and he adds, "He did not write for savants: he wrote for all mankind." No one now reads Buffon, while the works of Reaumur, who preceded him, are nearly as valuable as ever, since they are packed with careful observations.
The experiments of Redi, of Swammerdam, and of Vallisneri, and the observations of Reaumur, had no effect on Buffon, who maintained that, of the different forms of genesis, "spontaneous generation" is not only the most frequent and the most general, but the most ancient--namely, the primitive and the most universal.[126]
Buffon by nature was unsystematic, and he possessed little of the spirit or aim of the true investigator. He left no technical papers or memoirs, or what we would call contributions to science. In his history of animals he began with the domestic breeds, and then described those of most general, popular interest, those most known. He knew, as Malesherbes claimed, little about the works even of Linne and other systematists, neither grasping their principles nor apparently caring to know their methods. His single positive addition to zoological science was generalizations on the geographical distribution of animals. He recognized that the animals of the tropical and southern portions of the old and new worlds were entirely unlike, while those of North America and northern Eurasia were in many cases the same.
We will first bring together, as Flourens and also Butler have done, his scattered fragmentary views, or rather suggestions, on the fixity of species, and then present his thoughts on the mutability of species.
"The species" is then "an abstract and general term."[127] "There only exist individuals and _suites_ of individuals, that is to say, species."[128] He also says that Nature "imprints on each species its unalterable characters;" that "each species has an equal right to creation;"[129] that species, even those nearest allied, "are separated by an interval over which nature cannot pa.s.s;"[130] and that "each species having been independently created, the first individuals have served as a model for their descendants."[131]
Buffon, however, shows the true scientific spirit in speaking of final causes.
"The pig," he says, "is not formed as an original, special, and perfect type; its type is compounded of that of many other animals.
It has parts which are evidently useless, or which, at any rate, it cannot use." ... "But we, ever on the lookout to refer all parts to a certain end--when we can see no apparent use for them, suppose them to have hidden uses, and imagine connections which are without foundation, and serve only to obscure our perception of Nature as she really is: we fail to see that we thus rob philosophy of her true character, which is to inquire into the "how" of these things--into the manner in which Nature acts--and that we subst.i.tute for this true object a vain idea, seeking to divine the "why"--the ends which she has proposed in acting" (tome v., p. 104, 1755, _ex_ Butler).
The volumes of the _Histoire naturelle_ on animals, beginning with tome iv., appeared in the years 1753 to 1767, or over a period of fourteen years. Butler, in his _Evolution, Old and New_, effectually disposes of Isidore Geoffroy St. Hilaire"s statement that at the beginning of his work (tome iv., 1753) he affirms the fixity of species, while from 1761 to 1766 he declares for variability. But Butler a.s.serts from his reading of the first edition that "from the very first chapter onward he leant strongly to mutability, even if he did not openly avow his belief in it.... The reader who turns to Buffon himself will find that the idea that Buffon took a less advanced position in his old age than he had taken in middle life is also without foundation"[132]
(p. 104).
But he had more to say on the other side, that of the mutability of species, and it is these tentative views that his commentators have a.s.sumed to have been his real sentiments or belief, and for this reason place Buffon among the evolutionists, though he had little or no idea of evolution in the enlarged and thoroughgoing sense of Lamarck.
He states, however, that the presence of callosities on the legs of the camel and llama "are the unmistakable results of rubbing or friction; so also with the callosities of baboons and the pouched monkeys, and the double soles of man"s feet."[133] In this point he antic.i.p.ates Erasmus Darwin and Lamarck. As we shall see, however, his notions were much less firmly grounded than those of Erasmus Darwin, who was a close observer as well as a profound thinker.
In his chapter on the _Degeneration des Animaux_, or, as it is translated, "modification of animals," Buffon insists that the three causes are climate, food, and domestication. The examples he gives are the sheep, which having originated, as he thought, from the m.u.f.flon, shows marked changes. The ox varies under the influence of food; reared where the pasturage is rich it is twice the size of those living in a dry country. The races of the torrid zones bear a hump on their shoulders; "the zebu, the buffalo, is, in short, only a variety, only a race of our domestic ox." He attributed the camel"s hump to domesticity.
He refers the changes of color in the northern hare to the simple change of seasons.
He is most explicit in referring to the agency of climate, and also to time and to the uniformity of nature"s processes in causing variation.
Writing in 1756 he says:
"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."[134]
The Buffonian factor of the direct influence of climate is not in general of so thoroughgoing a character as usually supposed by the commentators of Buffon. He generally applies it to the superficial changes, such as the increase or decrease in the amount of hair, or similar modifications not usually regarded as specific characters. The modifications due to the direct influence of climate may be effected, he says, within even a few generations.
Under the head of geographical distribution (in tome ix., 1761), in which subject Buffon made his most original contribution to exact biology, he claims to have been the first "even to have suspected" that not a single tropical species is common to both eastern and western continents, but that the animals common to both continents are those adapted to a temperate or cold climate. He even antic.i.p.ates the subject of migration in past geological times by supposing that those forms travelled from the Old World either over some land still unknown, or "more probably" over territory which has long since been submerged.[135]
The mammoth "was certainly the greatest and strongest of all quadrupeds, but it has disappeared; and if so, how many smaller, feebler, and less remarkable species must have perished without leaving us any traces or even hints of their having existed? How many other species have changed their nature, that is to say, become perfected or degraded, through great changes in the distribution of land and ocean; through the cultivation or neglect of the country which they inhabit; through the long-continued effects of climatic changes, so that they are no longer the same animals that they once were. Yet of all living beings after man the quadrupeds are the ones whose nature is most fixed and form most constant; birds and fishes vary much more easily; insects still more again than these; and if we descend to plants, which certainly cannot be excluded from animated nature, we shall be surprised at the readiness with which species are seen to vary, and at the ease with which they change their forms and adopt new natures."[136]
The following pa.s.sages, debarring the error of deriving all the American from the Old World forms, and the mistake in supposing that the American forms grew smaller than their ancestors in the Old World, certainly smack of the principle of isolation and segregation, and this is Buffon"s most important contribution to the theory of descent.
"It is probable, then, that all the animals of the New World are derived from congeners in the Old, without any deviation from the ordinary course of nature. We may believe that, having become separated in the lapse of ages by vast oceans and countries which they could not traverse, they have gradually been affected by, and derived impressions from, a climate which has itself been modified so as to become a new one through the operations of those same causes which dissociated the individuals of the Old and the New World from one another; thus in the course of time they have grown smaller and changed their characters. This, however, should not prevent our cla.s.sifying them as different species now, for the difference is no less real though it dates from the creation.
_Nature, I maintain, is in a state of continual flux and movement.
It is enough for man if he can grasp her as she is in his own time, and throw but a glance or two upon the past and future, so as to try and perceive what she may have been in former times and what one day she may attain to._"[137]
Buffon thus suggests the principle of the struggle for existence to prevent overcrowding, resulting in the maintenance of the balance of nature:
"It may be said that the movement of Nature turns upon two immovable pivots--one, the illimitable fecundity which she has given to all species; the other, the innumerable difficulties which reduce the results of that fecundity, and leave throughout time nearly the same quant.i.ty of individuals in every species; ... destruction and sterility follow closely upon excessive fecundity, and, independently of the contagion which follows inevitably upon overcrowding, each species has its own special sources of death and destruction, which are of themselves sufficient to compensate for excess in any past generation."[138]
He also adds, "The species the least perfect, the most delicate, the most unwieldy, the least active, the most unarmed, etc., have already disappeared or will disappear."[139]
On one occasion, in writing on the dog, he antic.i.p.ates Erasmus Darwin and Lamarck in ascribing to the direct cause of modification the inner feelings of the animal modified, change of condition being the indirect cause.[140] He, however, did not suggest the idea of the transmission of acquired characters by heredity, and does not mention the word heredity.
These are all the facts he stated; but though not an observer, Buffon was a broad thinker, and was led from these few data to generalize, as he could well do, from the breadth of his knowledge of geology gained from the works of his predecessors, from Leibnitz to Woodward and Whiston.
"After the rapid glance," he says, "at these variations, which indicate to us the special changes undergone by each species, there arises a more important consideration, and the view of which is broader; it is that of the transformation (_changement_) of the species themselves; it is that more ancient modification which has gone on from time immemorial, which seems to have been made in each family or, if we prefer, in each of the genera in which were comprised more or less allied species."[141]
In the beginning of his first volume he states "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. We will recognize this gradation as the great work of nature; and we will observe it not only as regards size and form, but also in respect of movements and in the successive generations of every species."
"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 reasons. 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."[142]
This is all true, and was probably felt by Buffon"s predecessors, but it does not imply that he thought these forms had descended from one another.
"In thus comparing," he adds, "all the animals, and placing them each in its proper genus, we shall find that the two hundred species whose history we have given may be reduced to a quite small number of families or princ.i.p.al sources from which it is not impossible that all the others may have issued."[143]
He then establishes, on the one hand, nine species which he regarded as isolated, and, on the other, fifteen princ.i.p.al genera, primitive sources or, as we would say, ancestral forms, from which he derived all the animals (mammals) known to him.
Hence he believed that he could derive the dog, the jackal, the wolf, and the fox from a single one of these four species; yet he remarks, _per contra_, in 1753:
"Although we cannot demonstrate that the production of a species by modification is a thing impossible to nature, the number of contrary probabilities is so enormous that, even philosophically, we can scarcely doubt it; for if any species has been produced by the modification of another, if the species of a.s.s has been derived from that of the horse, this could have been done only successively and by gradual steps: there would have been between the horse and a.s.s a great number of intermediate animals, the first of which would gradually differ from the nature of the horse, and the last would gradually approach that of the a.s.s; and why do we not see to-day the representatives, the descendants of those intermediate species? Why are only the two extremes living?" (tome iv., p. 390). "If we once admit that the a.s.s belongs to the horse family, and that it only differs from it because it has been modified (_degenere_), we may likewise say that the monkey is of the same family as man, that it is a modified man, that man and the monkey have had a common origin like the horse and a.s.s, that each family has had but a single source, and even that all the animals have come from a single animal, which in the succession of ages has produced, while perfecting and modifying itself, all the races of other animals"
(tome iv., p. 382). "If it were known that in the animals there had been, I do not say several species, but a single one which had been produced by modification from another species; if it were true that the a.s.s is only a modified horse, there would be no limit to the power of nature, and we would not be wrong in supposing that from a single being she has known how to derive, with time, all the other organized beings" (_ibid._, p. 382).
The next sentence, however, translated, reads as follows:
"But no. It is certain from revelation that all animals have alike been favored with the grace of an act of direct creation, and that the first pair of every species issued fully formed from the hands of the Creator" (tome iv., p. 383).
In which of these views did Buffon really believe? Yet they appear in the same volume, and not at different periods of his life.
He actually does say in the same volume (iv., p. 358): "It is not impossible that all species may be derivations (_issues_)." In the same volume also (p. 215) he remarks: