Not so Buffon, born on his father’s estate in Burgundy in the same year as Linnaeus, whom he survived ten years, dying in 1788. His opinions, clashing as they did with orthodox creeds, were given in a tentative, questioning fashion, so that where ecclesiastical censure fell, retreat was easier. As has been seen in his submission to the Sorbonne, he was not of the stuff of which martyrs are made. Perhaps he felt that the ultimate victory of his opinions was sufficiently assured to make self-sacrifice needless. But, under cover of pretence at inquiry, his convictions are clear enough. He was no believer in the permanent stability of species, and noted, as warrant of this, the otherwise unexplained presence of aborted or rudimentary structures. For example, he says, “the pig does not appear to have been formed upon an original, special, and perfect plan, since it is a compound of other animals; it has evidently useless parts, or rather, parts of which it cannot make any use, toes, all the bones of which are perfectly formed, and which, nevertheless, are of no service to it. Nature is far from subjecting herself to final causes in the formation of her creatures.” Then, further, as showing his convictions on the non-fixity of species, he says, how many of them, “being perfected or degenerated by the great changes in land and sea, by the favours or disfavours of Nature, by food, by the prolonged influences of climate, contrary or favourable, are no longer what they formerly were.” But he writes with an eye on the Sorbonne when, hinting at a possible common ancestor of horse and ass, and of ape and man, he slyly adds that since the Bible teaches the contrary, the thing cannot be. Thus he attacked covertly; by adit, not by direct assault; and to those who read between the lines there was given a key wherewith to unlock the door to the solution of many biological problems. Buffon, consequently, was the most stimulating and suggestive naturalist of the eighteenth century. There comes between him and Lamarck, both in order of time and sequence of ideas, Erasmus Darwin, the distinguished grandfather of Charles Darwin.
Born at Eton, near Newark, in 1731, he walked the hospitals at London and Edinburgh, and settled, for some years, at Lichfield, ultimately removing to Derby. Since Lucretius, no scientific writer had put his cosmogonic speculations into verse until Dr. Darwin made the heroic metre, in which stereotyped form the poetry of his time was cast, the vehicle of rhetorical descriptions of the amours of flowers and the evolution of the thumb. The Loves of the Plants, ridiculed in the Loves of the Triangles in the Anti-Jacobin, is not to be named in the same breath, for stateliness of diction, and majesty of movement, as the De rerum Natura. But both the prose work Zoonomia and the poem The Temple of Nature (published after the author’s death in 1802) have claim to notice as the matured expression of conclusions at which the clear-sighted, thoughtful, and withal, eccentric doctor had arrived in the closing years of his life. Krause’s Life and Study of the Works of Erasmus Darwin supplies an excellent outline of the contents of books which are now rarely taken down from the shelves, and makes clear that their author had the root of the matter in him. His observations and reading, for the influence of Buffon and others is apparent in his writings, led him to reject the current belief in the separate creation of species. He saw that this theory wholly failed to account for the existence of abnormal forms, of adaptations of the structure of organs to their work, of gradations between living things, and other features inconsistent with the doctrine of “let lions be, and there were lions.” His shrewd comment on the preformation notion of development has been quoted (p. 20). The substance of his argument in support of a “physical basis of life” is as follows: “When we revolve in our minds the metamorphosis of animals, as from the tadpole to the frog; secondly, the changes produced by artificial cultivation, as in the breeds of horses, dogs, and sheep; thirdly, the changes produced by conditions of climate and of season, as in the sheep of warm climates being covered with hair instead of wool, and the hares and partridges of northern climates becoming white in winter; when, further, we observe the changes of structure produced by habit, as seen especially by men of different occupations; or the changes produced by artificial mutilation and prenatal influences, as in the crossing of species and production of monsters; fourth, when we observe the essential unity of plan in all warm-blooded animals—we are led to conclude that they have been alike produced from a similar living filament.” The concluding words of this extract make remarkable approach to the modern theory of the origin of life in the complex jelly-like protoplasm, or, as some call it, nuclein or nucleoplasm. And, on this, Erasmus Darwin further remarks: “As the earth and ocean were probably peopled with vegetable productions long before the existence of animals, and many families of these animals long before other animals of them, shall we conjecture that one and the same kind of living filament is and has been the cause of all organic life?” Nor does he make any exception to this law of organic development. He quotes Buffon and Helvetius to the effect—“that many features in the anatomy of man point to a former quadrupedal position, and indicate that he is not yet fully adapted to the erect position; that, further, man may have arisen from a single family of monkeys, in which, accidentally, the opposing muscle brought the thumb against the tips of the fingers, and that this muscle gradually increased in size by use in successive generations.” While we who live in these days of fuller knowledge of agents of variation may detect the minus in all foregoing speculations, our interest is increased in the thought of their near approach to the cardinal discovery. And a rapid run through the later writings of Dr. Darwin shows that there is scarcely a side of the great theory of Evolution which has escaped his notice or suggestive comment. Grant Allen, in his excellent little monograph on Charles Darwin, says that the theory of “natural selection was the only cardinal one in the evolutionary system on which Erasmus Darwin did not actually forestall his more famous and greater namesake. For its full perception, the discovery of Malthus had to be collated with the speculations of Buffon.”
In the Historical Sketch on the Progress of Opinion on the Origin of Species, which Darwin prefixed to his book, he refers to Lamarck as “the first man whose conclusions on the subject excited much attention;” rendering “the eminent service of arousing attention to the probability of all change in the organic, as well as in the inorganic world, being the result of law, and not of miraculous interposition.” Lamarck was born at Bezantin, in Picardy, in 1744. Intended for the Church, he chose the army, but an injury resulting from a practical joke cut short his career as a soldier. He then became a banker’s clerk, in which occupation he secured leisure for his favourite pursuit of natural history. Through Buffon’s influence he procured a civil appointment, and ultimately became a colleague of Cuvier and Geoffroy St. Hilaire in the Museum of Natural History at Paris. Of Cuvier it will here suffice to say that he remained to the end of his life a believer in special creation, or, what amounts to the same thing, a series of special creations which, he held, followed the catastrophic annihilations of prior plants and animals. Although orthodox by conviction, his researches told against his tenets, because his important work in the reconstruction of skeletons of long extinct animals laid the foundation of palæontology.
To Lamarck, says Haeckel, “will always belong the immortal glory of having for the first time worked out the Theory of Descent as an independent scientific theory of the first order, and as the philosophical foundation of the whole science of Biology.” He taught that in the beginnings of life only the very simplest and lowest animals and plants came into existence; those of more complex structure developing from these; man himself being descended from ape-like mammals. For the Aristotelian mechanical figure of life as a ladder, with its detached steps, he substituted the more appropriate figure of a tree, as an inter-related organism. He argued that the course of the earth’s development, and also of all life upon it, was continuous, and not interrupted by violent revolutions. In this he followed Buffon and Hutton. Buffon, in his Theory of the Earth, argues that “in order to understand what had taken place in the past, or what will happen in the future, we have but to observe what is going on in the present.” This is the keynote of modern geology. “Life,” adds Lamarck, “is a purely physical phenomenon. All its phenomena depend on mechanical, physical, and chemical causes which are inherent in the nature of matter itself.” He believed in a form of spontaneous generation. Rejecting Buffon’s theory of the direct action of the surroundings as agents of change in living things, he sums up the causes of organic evolution in the following propositions:
1. Life tends by its inherent forces to increase the volume of each living body and of all its parts up to a limit determined by its own needs.
2. New wants in animals give rise to new movements which produce organs.
3. The development of these organs is in proportion to their employment.
4. New developments are transmitted to offspring.
The second and third propositions were illustrated by examples which have, with good reason, provoked ridicule. Lamarck accounts for the long neck of the giraffe by that organ being continually stretched out to reach the leaves at the tree-tops; for the long tongue of the ant-eater or the woodpecker by these creatures protruding it to get at food in channel or crevice; for the webbed feet of aquatic animals by the outstretching of the membranes between the toes in swimming; and for the erect position of man by the constant efforts of his ape-like ancestors to keep upright. The legless condition of the serpent which, in the legend of the Garden of Eden, is accounted for on moral grounds, is thus explained by Lamarck: “Snakes sprang from reptiles with four extremities, but having taken up the habit of moving along the earth and concealing themselves among bushes, their bodies, owing to repeated efforts to elongate themselves and to pass through narrow spaces, have acquired a considerable length out of all proportion to their width. Since long feet would have been very useless, and short feet would have been incapable of moving their bodies, there resulted a cessation of use of these parts, which has finally caused them to totally disappear, although they were originally part of the plan of organization in these animals.” The discovery of an efficient cause of modifications, which Lamarck refers to the efforts of the creatures themselves, has placed his speculations in the museum of biological curiosities; but sharp controversy rages to-day over the question raised in Lamarck’s fourth proposition, namely, the transmission of characters acquired by the parent during its lifetime to the offspring. This burning question between Weismann and his opponents, involving the serious problem of heredity, will remain unsettled till a long series of observations supply material for judgment.
Lamarck, poor, neglected, and blind in his old age, died in 1829. Both Cuvier, who ridiculed him, and Goethe, who never heard of him, passed away three years later. The year following his death, when Darwin was an undergraduate at Cambridge, Lyell published his Principles of Geology, a work destined to assist in paving the way for the removal of one difficulty attending the solution of the theory of the origin of species, namely, the vast period of time for the life-history of the globe which that theory demands. As Lyell, however, was then a believer—although, like a few others of his time, of wavering type—in the fixity of species, he had other aims in view than those to which his book contributed. But he wrote with an open mind, not being, as Herbert Spencer says of Hugh Miller, “a theologian studying geology.” Following the theories of uniformity of action laid down by Hutton, by Buffon, and by that industrious surveyor, William Smith, who travelled the length and breadth of England, mapping out the sequence of the rocks, and tabulating the fossils special to each stratum, Lyell demonstrated in detail that the formation and features of the earth’s crust are explained by the operation of causes still active. He was one among others, each working independently at different branches of research; each, unwittingly, collecting evidence which would help to demolish old ideas, and support new theories.