For the sake of simplicity of demonstration I have assumed that a man marries his own daughter’s daughter, but through the classificatory principle all the features I have described would follow equally well if a man married the granddaughter of his brother, either in the narrow or the classificatory sense. There was one correspondence, according to which both the husband’s brother and the mother’s father were called _sibi_, which does not follow from the marriage with the own granddaughter, but would be the natural result of marriage with the daughter’s daughter of the brother--_i.e._, with a marriage in which _e_ was married by _A’s_ brother. I hope these examples will be sufficient to show how a number of features which might otherwise seem so absurd as to suggest a system of relationship gone mad become natural and intelligible, even obvious, if it were once the established practice of the people to marry the daughter’s daughter of the brother. Such inquiries as I was able to make confirmed the conclusion that the Pentecost marriage was with the granddaughter of the brother rather than with the daughter of the daughter herself. After I had been put on the track of the explanation by John Pantutun I had the chance of talking to only one native of Pentecost, unfortunately not a very good informant. From his evidence it appeared that the marriage I had inferred from the system of relationship even now occurs in the island, but only with the granddaughter of the brother, and that marriage with the own granddaughter is forbidden. The evidence is not as complete as I should like, but it points to the actual existence in the island of a peculiar form of marriage from which the extraordinary features of its system of relationship directly follow. When I returned to England I found that this marriage was not unique, but had been recorded among the Dieri of Australia,[15] where, as I have already mentioned, it is associated with peculiar features of nomenclature resembling those of Pentecost. [15] Howitt, _Native Tribes of South-East Australia_, pp. 164, 177. I must again ask, how are you going to explain the features of the Pentecost system psychologically? What psychological resemblance is there between a grandmother and a sister, between a mother-in-law and a daughter, between a brother-in-law and a grandfather? Apart from some special form of social relationship, there can be no such resemblances. Further, if there were such psychological resemblances, why should we know of their influence on nomenclature only in Pentecost and among the Dieri? The features to be explained are definitely known to exist in only two systems of the world, and it is only among the peoples who use these two systems that we have any evidence of that extraordinary form of marriage of which they would be the natural consequence. * * * * *