[71] The Evolution Theory, II, 264.
[72] I take this from J. T. Cunningham’s Sexual Dimorphism, p. 16.
[73] Useless structures and organs are regarded by Weismann, and I think with justice, as in some degree unfavourable. They make demands on the organism for nourishment, and are thus in the position of non-productive members of a working family.
[74] Op. cit., p. 73. See Appendix [B.]
[75] Wallace, Darwinism, p. 24.
[76] Animal Coloration, p. 252.
[77] Poulton, The Colours of Animals, p. 238.
[78] Ibid., p. 237.
[80] Eng. trans. revised from fifth German edition, 1903, p. 3.