The only serious attempt to _explain_ the derivation of new species from old ones that came before Lyell was that of the illustrious Lamarck. Very noteworthy was the work of that old wounded French soldier, afflicted in his later years as he was by blindness. By his early labours, Lamarck had attained a considerable reputation as a botanist, and later in life he turned his attention to zoology, and then to palaeontology and geology. In zoology, he did for the study of invertebrate animals what his great contemporary Cuvier was accomplishing for the vertebrates; but, with regard to the origin of species, he arrived at conclusions directly at variance with those of his distinguished rival. We are indebted to Professor Osborn[85] for calling attention to that remarkable, but little known work of Lamarck's--_Hydrogéologie_--published in 1802, seven years before his _Philosophie Zoologique_ appeared. This work is especially interesting as showing to how great an extent--as in the case of Darwin, Wallace and others--it was geological phenomena which played an important part in leading Lamarck to evolutionary convictions. "In Geology," Professor Osborn writes, 'Lamarck was an ardent advocate of uniformity, as against the Cataclysmal School. The main principles are laid down in his _Hydrogéologie_, that all the revolutions of the earth are extremely slow. "For Nature," he says, "time is nothing. It is never a difficulty, she always has it at her disposal; and it is for her the means by which she has accomplished the greatest as well as the least results[86]."' On the subject of subaerial denudation (the action of rain and rivers in wearing down the earth's surface), Lamarck's views were as clear and definite as those of Hutton himself; though it is almost certain that he could never have seen, or even heard of, the writings of the great Scottish philosopher. On some other questions of geological dynamics, however, it must be confessed that Lamarck's views and speculations were rather crude and unsatisfactory. In his _Philosophie Zoologique_, published in the same year that Charles Darwin was born (1809), Lamarck brought forward a great body of evidence in favour of evolution, derived from his extensive knowledge of botany, zoology and geology. He showed how complete was the gradation between many forms ranked as species, and how difficult it was to say what forms should be classed as 'varieties' and what as 'species.'