Page:Popular Science Monthly Volume 20.djvu/625

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side, to know what can be made of the case in good hands. I am glad he has been courageous enough, and logical enough, to admit that his argument, if pushed as far as it must go, would prove that men may have come from the orang-outang. But, after all, what changes species may really undergo! How impossible will it be to distinguish and lay down a line beyond which some of the so-called extinct species have never passed into recent ones!

The last two sentences show how, even then, Lyell was trembling upon the brink of the truth. He had got in the thin end of the wedge; he was prepared to admit the first infinitesimal in the long series whose sum makes up at last the difference between himself and the amoeba: and yet he refused to go any further.

Time after time, for many years, we find the same thing cropping up again. The question is always before him, though he wavers much in the way he regards it. It seems to fascinate him and draw him on; even when he is fighting against it, it appeals to him as the natural complement of his other beliefs. In 1830 he writes to his sister from Paris:

This morning all my Etna shells were examined; out of sixty-three only three species not known to inhabit the Mediterranean, yet the whole volcano nearly is subsequent to them, and rests on them. They lived, on a moderate computation, one hundred thousand years ago, and, after so many generations, are quite unchanged in form. It must, therefore, have required a good time for orang-outangs to become men on Lamarckian principles.

Any one can see the falsity of this reasoning, which would imply an absolute uniformity in the rate of change in nature everywhere. A little later, in 1836, he writes to Sir John Herschel:

In regard to the origination of new species, I am very glad to find that you think it probable that it may be carried on through the intervention of intermediate causes. . . . An insect may be made in one of its transformations to resemble a dead stick, or a leaf, or a lichen, or a stone, so as to be somewhat less easily found by its enemies; or, if this would make it too strong, an occasional variety of the species may have this advantage conferred on it; or, if this would be still too much, one sex of a certain variety. Probably there is scarcely a dash of color on the wing or body of which the choice would be quite arbitrary, or which might not affect its duration for thousands of years.

In some ways this is marvelously near Darwin; but in others it differs toto cœlo; for Lyell does not see that these variations could arise "spontaneously," that is to say, in the ordinary course of small differences of antenatal conditions; he sets them all down directly to "the Presiding Mind." Nor does he see that they might result at last in the production of new species. Indeed, the context, which I have suppressed, takes off much from the superficial air of anticipating Darwin, which the passage nakedly quoted undoubtedly bears. A year later he tells his sister—

The latest news is that two fossil monkeys have at last been found one in India, contemporary with extinct quadrupeds, but not very ancient, Pliocene,