Falling in Love; With Other Essays on More Exact Branches of Science

Long before Darwin's book appeared evolution had been a recognised force in the moving world of science and philosophy. Natural selection lays almost all the stress on the last point, and hardly any at all upon the first one. They are thus essentially degenerate creatures: they have found the conditions of life too easy for them, and they have reverted to something so low and simple that they are almost plant-like in some of their habits and peculiarities. Gathering strength all the time for the coming contest, increasing constantly in size of brain and keenness of intelligence, the true mammals were able at last, towards the close of the secondary ages, to enter the lists boldly against the gigantic saurians.