Note 37 — Chapter XXV · LAWS OF VARIATION, continued.—CORRELATED VARIABILITY.

Mr. Herbert Spencer (‘Principles of Biology,’ 1864, vol. i. pp. 452, 468) takes a different view; and in one place remarks: “We have seen reason to think that, as fast as essential faculties multiply, and as fast as the number of organs that co-operate in any given function increases, indirect equilibration through natural selection becomes less and less capable of producing specific adaptations; and remains fully capable only of maintaining the general fitness of constitution to conditions.” This view that natural selection can do little in modifying the higher animals surprises me, seeing that man’s selection has undoubtedly effected much with our domesticated quadrupeds and birds.