[647] Darwin, Descent of Man, chap. viii, 222 ff.; Espinas, Des sociétés animales, 323 ff. Cf. Groos, Die Spiele der Thiere, 129 ff.
[648] Westermarck, op. cit., 157; Sachs, Text-Book of Botany, 897; Darwin, op. cit., chap. viii; Kulischer, Die geschlechtliche Zuchtwahl, in ZFE., VIII, 140 ff., who regards the dance as originally a form of wooing. Such is also the view of Espinas, op. cit., 305 ff.; and Groos, op. cit., 257 ff., 263 ff.
[649] Westermarck, op. cit., 159, 253; Darwin, op. cit., chap. xiii; Wallace, Darwinism, 282 ff.
[650] Martius, Rechtszustande, 589; idem, Ethnographie, I, 111; Waitz, Anthropologie, III, 101; Darwin, op. cit., chap. xix, 561 ff.; Lubbock, Origin of Civilization, 101 ff.; and especially Westermarck, op. cit., 159-63, who gives many examples.
[651] Darwin, op. cit., chap. xiii, 367; chap. viii, 214 (prolonged courtship of animals). Cf. Westermarck, op. cit., 159.
[652] Darwin, op. cit., chap. xxi, 614.
[653] Ibid., chap. viii, 211; cf. ibid., 496, 554.
[654] Westermarck, op. cit., 241.
[655] Darwin, op. cit., chap. xvi, 496.
[656] Wallace, Darwinism, 268-300; also his Tropical Nature, 221-48.