[43] “Organic Evolution,” pp. 223, 263, 258, 279, 276, 298.

[44] “Essays on Heredity” (1889), p. 91.

[45] Op. cit., pp. 196–198.

[46] Professor Henry Osborn has also indicated the relationship referred to.

[47] “The Play of Animals,” p. 64.

[48] “Solitary Wasps,” p. 236.

[49] See D. Sharp, “Cambridge Natural History,” “Insects,” part ii., p. 293, and the original authorities cited on p. 294.

[50] This and the three succeeding paragraphs are taken from “Animal Life and Intelligence,” p. 425.

[51] “Animal Intelligence,” p. 59.

[52] “Instincts and Habits of the Solitary Wasps,” p. 55.