But the argument for the pre-human origin of the elements of marriage and the family does not rest merely upon precedents of sexual habits. It is based rather upon the entire experience of animals in the hard struggle for existence. That struggle, as Hellwald suggests, forced upon them primarily the problem of food-supply, the need of a sort of economic co-operation, more lasting in its results than the pairing instinct. It is the entire social, mental, and moral product of animal experience, of living together, so well described among others by Espinas, Schäffle, Groos, and Wundt, which man in some measure inherited as a rich legacy from his humbler predecessor.[290] Accordingly Westermarck believes that marriage was probably "transmitted to man from some ape-like ancestor, and that there never was a time when it did not occur in the human race."[291] With Starcke, and in harmony with the view of Hellwald already quoted, he holds that marriage and the family cannot rest upon the sexual impulse alone. This is too transitory. Among animals it is obvious that "it cannot be the sexual instinct that keeps male and female together for months and years," for the "generative power is restricted to a certain season;" and it seems highly probable that among men a pairing season prevailed in ancient times. Thus the "wild Indians of California, belonging to the lowest races on earth," are said to "have their rutting seasons as regularly as have the deer, the elk, the antelope, or any other animals."[292] According to Powers, the California Kabinapek "are extremely sensual. In the spring when the wild clover is lush and full of blossoms and they are eating it to a satiety after the famine of winter, they become amorous. This season, therefore, is a literal Saint Valentine's Day with them, as with the natural beasts and birds of the forest."[293] The Tasmanians, the Australian Watch-an-dies, and various other peoples appear to show evidences of the same habit.[294] Vignoli reaches a similar conclusion. "The family union in which man originally finds himself is not an essentially human but likewise an animal fact, since that mode of common social life is found with the greater part of animals and always among the higher. It is the necessity of rearing the young which unites the parents and gives them a common life for a shorter or longer period; indeed in some species this marriage of love and care continues throughout their whole existence. Hence the fact of family sociality is not an exclusive product of humanity, but of the universal laws of the whole animal life upon the earth. Let it not be asserted that in man affection between the sexes and toward their offspring ... is more active, more intense, and more lasting; for it manifests itself with equal strength and sometime with equal duration between animals and toward their young. Thus man loves, cohabits, and lives socially in a primitive family community only because he is an animal and moreover