[8] Ibid. I. pp. 12-17.
[9] Appendix to "Mental Evolution in Animals," pp. 370, 383; see also "The Descent of Man," I. p. 102 et seq.; and "Nature" for Feb. 13, 1873, introduction to a letter to the editor from William Higginson.
[10] P. 103.
[11] Pp. 160, 161.
[12] P. 161.
[13] See also p. 171. And, p. 172, sympathy is designated as "a fundamental element of the social instincts."
[14] P. 178.
[15] Pp. 174, 178.
[16] P. 173.
[17] "Descent of Man," I. p. 199, etc.