A creature which gets its food, as do many of the lower species, without exertion of its own, does not act egoistically, nor does the animal which, in the natural course of its growth, brings forth young by spontaneous division; but that animal may do so which acquires its food by means of any voluntary actions, however insignificant, or which voluntarily protects and cares for its young; and such voluntary action increases rather than decreases with greater organization. Real egoism begins with the voluntary acquisition of food, a process continued in the forced excretion of the young. But since this action benefits the second generation, we may regard it as the connecting link between egoism and altruism. It is not purely altruistic; altruism proper begins with the nourishment and care of the young. And to what degree we have a right to consider even this as really altruistic can be determined only by further investigation. The emptying of the milk-glands is combined with pleasure; it may therefore be regarded as primarily egoistic, and furnishes us with a further example of the development of altruism from egoism. Altruism increases, not only with higher organization, but also with a higher development of social life. The beginnings of society are to be found in the family life of animals; the most primitive form of this is the temporary, voluntary association of male and female among the higher species; that is, the anthropoids and vertebrates. On this merely temporary association follows, as a higher stage, the lasting family union, which exists among comparatively few animals. The so-called "states" of the animals are, in their most typical instances, nothing but families living in a condition of polyandry.