Page:Popular Science Monthly Volume 76.djvu/48

44 of the Neodarwinians so far as natural selection goes. By far the most important nexus between Darwin and Weismann, when it comes to the deeper reaches of biological theory, is through Darwin's pangenesis hypothesis and Weismann's germ-plasm-determinant doctrine. This I treat at length elsewhere. It may be left to one side here because of its relative unimportance as touching Darwin's work proper, though of fundamental importance to an exhaustive discussion of the present status of biological philosophy.

Mr. Wallace's ungrudging recognition of Darwin's towering genius as compared with his own is one of the particularly bright and inspiriting examples of what personal relationship between men may be. And to Mr. Wallace is the greater honor because his was the lesser intellectual endowment and achievement.

Turning from Mr. Wallace's beautifully deferential attitude toward his friend, to the facts upon which he based this, what do we find?

We have already seen that Darwin had convinced himself of the truth of descent with modification before he thought of natural selection, and that it was the essay of Malthus on population that gave him the idea of struggle and survival. On December 22, 1857, he said in a letter to Mr. Wallace:

It should be remembered that Malthus's essay was read in 1837.

The circumstances under which Mr. Wallace became the co-propounder of evolution and co-discoverer of natural selection are told by himself. He says: