Among a number of branches of the Dakotas the evidence is of a different kind, being derived from similar nomenclature for the cross-cousin and certain kinds of brother- and sister-in-law. Morgan[23] has recorded eight systems, all of which show the features in question, but I will consider here only that of the Isauntie or Santee Dakotas, which was collected for him by the Rev. S. R. Riggs. Riggs[24] and Dorsey[25] have given independent accounts of this system which are far less complete than that given by Morgan, but agree with it in all essentials. [23] _Loc. cit._ [24] _Dakota Grammar, Texts, and Ethnography: Contributions to North American Ethnology_, Washington, vol. ix. [25] Preface to above. In this system a man calls the son of his mother’s brother or of his father’s sister _ta-hang-she_ or _tang-hang-she_, while his wife’s brother and his sister’s husband are _ta-hang_ or _tang-hang_. Similarly, a woman calls her cross-cousin _she-chay-she_, while her husband’s brother and her sister’s husband are called _she-chay_. The terms for brothers-in-law are thus the same as those for cross-cousins with the omission of the suffix _she_. One of these resemblances, that when a woman is speaking, has been cited by Professor Kroeber[26] as an example of the psychological causation of such features of relationship as I am considering in these lectures. He rejects its dependence on the cross-cousin marriage and refers the resemblance to the psychological similarity between a woman’s cousin and her brother-in-law in that both are collateral relatives alike in sex, of the same generation as the speaker, but different from her in sex. [26] _Op. cit._, p. 82. As we have seen, however, the Dakota correspondence is not an isolated occurrence, but fits in with a number of other features of the systems of cognate peoples to form a body of evidence pointing to the former prevalence of the cross-cousin marriage. There is also indirect evidence leading in the same direction. In Melanesia there is reason to believe that the cross-cousin marriage stands in a definite relation to another form of marriage, that with the wife of the mother’s brother. If there should be evidence for the former existence of this marriage in North America, it would increase the probability in favour of the cross-cousin marriage.