that state whereunto they are called.” But what is the nature of the social organisation to which the system of group marriage belongs? At the present time nearly all the existing Australian tribes are divided into four classes, into one of which every individual is born. The members of each class are supposed to trace their descent to the same common female ancestor, they are treated as of the same degrees of kinship to each other, and they are not allowed to intermarry. There is reason to believe that originally, perhaps when the ancestors of all the existing tribes resided in the same neighbourhood, each tribe consisted of only two classes. In this case, the law of group marriage, under the regulations as to marriage and descent just mentioned, would require that all the members of each class should be real or tribal brothers and sisters of each other, and the husbands and wives of all the members of the other class. The theoretical result would be, that all the men of each class would have their wives in common, and all the women of each class their husbands in common. Whether the number of individuals in each group was large or small, the result would be the same. In practice, the exercise of the extended marriage right would be restricted to a few individuals, but that its existence is generally understood is shown by the statement of a native servant, who had travelled far and wide in Australia, that “he was furnished with temporary wives by the various tribes with whom he sojourned in his travels; that his right to those women was recognised as a matter of course; and that he could always ascertain whether they belonged to the division into which he could legally marry, though the places were a thousand miles apart, and the languages quite different.” This particular case might, perhaps, be explained as an extreme example of the granting of sexual hospitality; but Mr. Fison refers to several facts which prove the reality of the relationships arising out of group marriage, and therefore of this system itself. He states that an Australian “has the rights of a brother, and he acknowledges the duties of a brother, towards every man of his own group; and he can no more marry a woman of a group which is ‘sister’ to his own than we can marry our own sister.” Among the Australians, as among some other races who are supposed to have had at one time a similar marriage system, a mother-in-law and a son-in-law mutually avoid each other. This conduct is based on the fact that the mother-in-law belongs to the class of women over whom the son-in-law has a marital right, but as she is _specially_ forbidden to him they must keep out of each other’s way. Again, the incidents attendant on adoption are in accordance with the reality of group relationships. A person who is adopted into a gens or family “forthwith abandons all the relationships of his own gens, and takes those of the gens into which he is adopted,” a result