But if polygamy is frequent with mammals, it is far from being the conjugal régime universally adopted; monogamy is common, and is sometimes accompanied by so much devotion, that it would serve as an example to human monogamists.
It is important also to notice that, in regard to animals, the mode of sexual association may vary without much difficulty. No species is of necessity and always restricted to such or such a form of sexual union. An animal belonging to a species habitually monogamous may very easily become polygamous. In short, there does not seem to be any relation between the degree of intelligence in a species and its conjugal customs.
In the following chapters it will be seen that, in great measure, these observations do not apply exclusively to animals.
FOOTNOTES:
[29] Espinas, Soc. Animales, pp. 343, 344.
[30] Ibid. pp. 344, 345.
[31] Espinas, Soc. Animales, pp. 336-396.
[32] Darwin, Descent of Man, p. 375.
[33] Lortet, Comptes rendus de l’Académie des Sciences, 1878.
[34] Darwin, Descent of Man, p. 379.