[73] Argentine Ornithology, Vol. I. p. 148; quoted by Havelock Ellis, Psychology of Sex, Vol. III. p. 33.
[74] Wallace, Darwinism, p. 284; also J. Lewis Bonhote, The Birds of Britain, p. 319.
[75] Letourneau, Evolution of Marriage, pp. 14-15.
[76] Wallace, Darwinism, p. 287.
[77] H.O. Forbes, A Naturalist's Wanderings, p. 131; quoted by Havelock Ellis, Psychology of Sex, Vol. III. pp. 33-34.
[78] Darwin, Descent of Man, p. 438.
[79] Epinas, Soc. animales, p. 326; and Letourneau, Evolution of Marriage, p. 14.
[80] Darwin, Descent of Man, p. 438; Letourneau, op. cit., p. 13.
[81] Annali del Museo civico di storia naturale di Genova, t. IX. fasc. 3-4, 1877, quoted by Letourneau, whose account I give; op. cit., p. 14.
[82] Havelock Ellis, Psychology of Sex, Vol. III. pp. 18-24, has discussed this question at some length. The brief account I have given is a summary of his view. I take this opportunity of gratefully acknowledging the great help I have gained from the illuminating and valuable works of Mr. Ellis.