[57] Dr. Lindley Kemp, Indications of Instinct.
[58] Handcock on Instinct, p. 18.
[59] Introd. Ent., ii, p. 465.
[60] Origin of Species, 'Cell-making Instinct.'
[61] Origin of Species, p. 225.
[62] Mind in Animals, pp. 252-3.
[63] For a complete account of these habits see Bingley, Animal Biography, vol. iii., pp. 272-5.
[64] Mém. sur les Insectes, tom. vi., p. 39.
[65] Vol. i., pp. 22-3 (3rd ed.).
[66] Vol. xvii., p. 373.