of a change in the mode of descent. Once turned into a fresh path by the necessity of showing how the correspondence could have arisen out of a matrilineal condition, it was not long before I saw how it might be accounted for in a very different way. I saw that the correspondence would be the natural result of a form of social organisation in which it was the practice to marry a grandmother, viz., the wife of the father’s father. Not only did this form of marriage explain the second peculiar feature of the Fijian system, viz., the classing of the son’s wife with the mother, but it would also account for several features of the Buin system which would otherwise be difficult to understand. [16] _Zeitsch. f. vergleich. Rechtswiss._, 1910, xxiii., 330. [Illustration: DIAGRAM 5. A = b | | C = d | | +-------+-------+ | | | E F f ] If, as shown in Diagram 5, _E_ marries _b_, the wife or widow of his father’s father, he, who had previously been the elder brother of _F_ and _f_, now comes to occupy the position of their father’s father, while _d_, the mother of _E_, will now come to stand to him in the relationship of son’s wife. I need only mention here one of the features of the Buin system which can be accounted for by means of this marriage. The term _mamai_ is used, not only for the elder sister and for the elder brother’s wife, but it is also applied to the father’s mother; that is, the wife of the elder brother is designated by the same term as the wife of the father’s father, exactly as must happen if _E_ marries _b_, the wife of his father’s father. A number of extraordinary features from two Melanesian islands collected by two independent workers fit into a coherent scheme if they have been the result of a marriage in which a man gives one of his wives to his son’s son during his life, or in which this woman is taken to wife by her husband’s grandson when she becomes a widow. If the practice were ever sufficiently habitual to become the basis of the system of relationship, we can be confident that it is the former of these two alternatives with which we have to do. If you are still so under the domination of ideas derived from your own social surroundings that you cannot believe in such a marriage, I would remind you that there is definite evidence from the Banks Islands that men used to hand over wives to their sisters’ sons. It is not taking us so much into the unknown as it might appear to suppose that they once also gave their wives to their sons’ sons.