The exogamy hypothesis, with special reference, to the phenomena just mentioned, has recently been discussed by Professor Kroeber.[50] He accepts the empirical correlation between exogamy and the merging of lineal and collateral kin with bifurcation of the parental lines, but interprets it as due rather to the differentiation of male and female lines of descent than to exogamy itself, which latter he regards as ‘perhaps a common but not necessary development, and an overlying development of the former’. “The basic condition,” argues Dr. Kroeber, “would be that in which a woman would be felt to be a very different thing from a man in relationship--less perhaps as an existing individual than as a factor in the relations of other people. Once this point of view prevailed, cross-cousins would necessarily be felt to be something very different from parallel cousins, and cross-uncles and aunts from parallel ones; and the distinction would find expression in nomenclature.” Accentuation of the male and female lines of descent with greater weighting of the one would possibly lead to clan groups. As a theory of the origin of exogamous groups I have no particular objection to offer to the foregoing. For reasons to be stated below (p. 163) I heartily concur in the assumption that the family, in America at all events, preceded the clan or gens. If I understand him correctly, Dr. Kroeber’s remarks merely paraphrase the fact of this sequence. But I do not see that acceptance of his view on this point involves a rejection of the influence of the clan when that has once developed. Of course it is not directly exogamy that is expressed but the alignment in groups which exogamy brings about. On Dr. Kroeber’s assumption it is unintelligible why father’s sister’s son and mother’s brother’s son should so frequently be classed together since the one is clearly related through the father, the other through the mother. We can hardly credit the native mind with a tendency to algebraic equalization of a plus and minus quantity by which the product of a male and a female relationship shall be standardized by a common designation. Generally speaking, Dr. Kroeber’s factors explain only bifurcation but not merging. The fact that even remote father’s cousins are grouped with the father is what the clan or gentile hypothesis explains over and above the dichotomy of relatives. That such merging occurs among tribes with definite exogamous groups, and generally not in loosely organized ones, can hardly be an accident. Dr. Kroeber’s case is, however, weakest as regards the Hidatsa and Omaha variants of the Dakota scheme. If ‘unilaterality of descent’ rather than clan or gentile affiliation is the determinant here, then why is the Hidatsa variant uniformly found among matrilineal tribes and the Omaha variant uniformly with a gentile system? In other words, why does not the Omaha call his father’s sister’s son ‘father’ and his father’s sister’s daughter ‘aunt’? The