Among the mammals polygamy is frequent, and there are cases of the most brutal promiscuity, where the males and females unite and separate at chance meetings, without any care for the family arising in the mind of the male. Polygamous unions are especially common among species with sociable habits who live in hordes. Sociability probably arises through individual weakness. Animals that are badly armed for fierce combats, and that have, besides, difficulty in obtaining food are glad to live in association. Thus the ruminants live in hordes or polygamous groups, composed of females and young subject to a male who protects them, expelling his rivals, and being a veritable chief of a band.[52] The conditions of the nursery and early life of the young are changed necessarily by these different habits. In the first place, the ruminants are wanderers, and travel long distances in search of food and water. Thus there is no permanent home and no nursery, and the mothers make no preparation beforehand for the young. They retire for a few minutes to a thicket, where they drop the calves or lambs. Families are small, and one is the usual number at a birth. The young are not born helpless, as is the case among the young carnivores where there is a settled nursery, but are clothed, have their eyes open, and their senses are very alert. In a very short time, almost as soon as their mother has licked them clean, they are ready to follow her; and they join the herd, if the animals are gregarious. The mothers show marked affection to the young, but it would seem to be the business of the young one rather to follow and stick to the mother than for the mother, as amongst the carnivores, to take the lead in the affections. There is no real training of the young by the mother. Sometimes, if there is a herd, the males will combine to defend the group of the females and their young; but more frequently there is a family party, consisting of one or possibly two males, with their several wives and children.[53] Many different animals live in this manner in familial groups. The moufflons of Europe and of the Atlas, for instance, form polygamous social groups in the breeding season.[54] Among the walrus, the male, who is of a very jealous temperament, collects around him from thirty to forty females, making altogether a polygamous family sometimes amounting to a hundred and twenty individuals.[55] Again, the male of the Asiatic antelope is inordinately polygamous; he expels all his rivals, and forms a harem numbering sometimes a hundred females. It should be noted that polygamic régime does not appear to lessen the affectionate sentiment in the females towards their tyrant lord. There are many examples of the most oppressed females being faithful wives. And so much is this so that the conclusion is almost forced upon us that the female animal likes servitude.[56]