[281] Brehm, Bird-Life, 324; Westermarck, op. cit., 11, 482, 502.
[282] Hellwald, op. cit., 25, 26.
[283] Description of Troglodytes Gorilla, 9 ff.; Westermarck, op. cit., 13.
[284] Du Chaillu, Explorations and Adventures in Equatorial Africa, 349; Westermarck, op. cit., 14. But see Hellwald, op. cit., 23.
[285] Cf. Darwin, Descent of Man, 108, 217 ff., 590, 591, who is cautious in his statement as to the rule among the quadrumana. Kautsky, "Entstehung der Ehe und Familie," Kosmos, XII, 198 ff., gives some interesting illustrations of marriage among animals; and see Espinas, op. cit., 444 ff.; Atkinson, Primal Law, 219-25.
[286] Kohler, Zur Urgeschichte der Ehe, 6, 7; Lippert, Kulturgeschichte, I, 72, 73.
[287] Hellwald, op. cit., 26, 27.
[288] Op. cit., 444; cf. Hellwald, op. cit., 40-42.
[289] Westermarck, op. cit., 14-19. Hildebrand, Ueber das Problem einer allgemeinen Entwicklungsgeschichte, 23 ff., maintains the existence of monogamy in what he holds to be the first culture-stage, that of the chase. A similar result is reached by Mucke, Horde und Familie, 59 ff., passim: Kautsky, op. cit., 190 ff.; Grosse, Die Formen der Familie, as above summarized.
[290] For the social systems among animals, even insects, see Schäffle, Bau und Leben des socialen Körpers, 20 ff.; Wundt, Menschen und Tierseele, 369 ff., 447 ff.; Groos, Spiele der Thiere, 147 ff., 162 ff., 230 ff.; and especially Espinas, op. cit., 207 ff., 274 ff., 458 ff., 543 ff. Compare Houzeau, Étude sur les facultés mentales des animaux; and the other authors on this subject cited in Bibliographical Note III.