show that it was formerly more widespread among them.  “In the Urabunna tribe, for example,” say Spencer and Gillen, “a group of men actually do have, continually and as a normal condition, marital relations with a group of women.  This state of affairs has nothing whatever to do with polygamy any more than it has with polyandry.  It is simply a question of a group of men and a group of women who may lawfully have what we call marital relations.  There is nothing whatever abnormal about it, and, in all probability, this system of what has been called group marriage, serving as it does to bind more or less closely together groups of individuals who are mutually interested in one another’s welfare, has been one of the most powerful agents in the early stages of the upward development of the human race” (Spencer and Gillen, Northern Tribes of Central Australia, p. 74; cf.  A.W.  Howitt, The Native Tribes of South-East Australia).  Group-marriage, with female descent, as found in Australia, tends to become transformed by various stages of progress into individual marriage with descent in the male line, a survival of group-marriage perhaps persisting in the much-discussed jus primae noctis. (It should be added that Mr. N.W.  Thomas, in his book on Kinship and Marriage in Australia, 1908, concludes that group-marriage in Australia has not been demonstrated, and that Professor Westermarck, in his Origin and Development of the Moral Ideas, as in his previous History of Human Marriage, maintains a skeptical opinion in regard to group-marriage generally; he thinks the Urabunna custom may have developed out of ordinary individual marriage, and regards the group-marriage theory as “the residuary legatee of the old theory of promiscuity.”  Durkheim also believes that the Australian marriage system is not primitive, “Organisation Matrimoniale Australienne,” L’Annee Sociologique, eighth year, 1905).  With the attainment of a certain level of social progress it is easy to see that a wide and complicated system of sexual relationships ceases to have its value, and a more or less qualified monogamy tends to prevail as more in harmony with the claims of social stability and executive masculine energy.

The best historical discussion of marriage is still probably Westermarck’s History of Human Marriage, though at some points it now needs to be corrected or supplemented; among more recent books dealing with primitive sexual conceptions may be specially mentioned Crawley’s Mystic Rose, while the facts concerning the transformation of marriage among the higher human races are set forth in G.E.  Howard’s History of Matrimonial Institutions (3 vols.), which contains copious bibliographical references.  There is an admirably compact, but clear and comprehensive, sketch of the development of modern marriage in Pollock and Maitland, History of English Law, vol. ii.