TERMS). Whether exogamy is genetically connected with incest, i.e., whether it is an extension of the tabu on intercourse and marriage within the family, or an independent institution, is a debated question (see Westermarck, H.H.M., II., pp. 192-218; Frazer, Totemism and Exogamy, vol. IV., passim; Malinowski, Sex and Repression in Savage Society, part IV.).
Exogamy embraces the widest number of people, where it is based on the dual organisation and debars from intercourse or marriage one half of the tribesmen and tribeswomen (cf. DUAL ORGANISATION). Normally exogamy is an attribute of clan, i.e., of the group of people who trace their descent to a common an cestor, have in most cases the same totem, and fulfill a number of functions together (see CLAN, TOTEM, KINSHIP). The clans are sometimes a subdivision of the tribe, based numerically on the dual principle, as where we have two, four or eight clans. At times there is an odd and more or less considerable number of clans, and exogamy is enforced only within each of these divisions. The prohibitions as a rule apply unilaterally (Iroquois, Huron, Lenape, Mohegan, Miami, Shawnee, Creek, Sauk, Fox, Kickapoo, Black foot, Dakota, Seminole of N. America; Arawak and Goajiro of S. America; Tungus, Yakut, Samoyed, Ostyak, Tartars of N.E. Asia; various aboriginal peoples of India; Torres Straits Is landers, Papuans, Melanesians, Polynesians and Micronesians of Oceania; Hottentot, S.E. Bantu, Anyanja, Wayao, Awemba, Mak ololo, Akonde, Masai, Akamba, Baganda and other E. African tribes; Ashanti and other W. African tribes). Only in a few cases has exogamy to be observed with regard to the clans of both parents (Omaha, Osage of N. America; certain Naga tribes of Assam; S. Massim of Melanesia; Herero, Lango of Africa).
A specially complex set of conditions prevails in the tribes of C. Australia, where there is a twofold division into (a) totemic clans, which are not strictly exogamous; and (b) matrimonial classes, which strictly correspond to kinship divisions, and which are not only exogamous, but regulate marriage to the extent that a member of one of them has to marry into one and one only of the remaining three or seven classes, as the case may be (see AUSTRALIA : Ethnology).
25. The Forms of Marriage.—From the foregoing description it will be clear that there is a considerable range within which the constitution of marriage can vary. For as we have seen there can be many different arrangements in the domestic, legal, eco nomic and ceremonial sides of marriage, and each of their mani fold combinations constitutes a distinct form of marriage.
The term "form of marriage" has been as a rule applied to what might be called the numeric variation in marriage, i.e., the varia tion according to the number of consorts united to each other; and the main "forms of marriage" usually listed are monogamy, polygyny, polyandry and group-marriage. To deal with this classi fication adequately it is necessary to distinguish hypothetical assumptions from actually existing social arrangements. From this point of view we can at once eliminate "group-marriage," since our previous analysis (see above, 5) has shown that the pirrauru relationship of Australia and similar institutions among the Eskimo and in Siberia can not in their parental, economic, legal or re ligious functions be regarded as a form of marriage.
26. Polyandry.—This is the name given to a union in which several men are legally bound in marriage to one woman. Poly andry is the rarest of the numeric varieties of marriage, and un fortunately the one on which, in spite of its great theoretical importance, we possess but very meagre and inadequate infor mation. Polyandry is not found among any of the more primitive peoples, and its distribution is almost completely confined to the highlands of S. India and C. Asia, with isolated exceptions, such as one African tribe (Bahima) and some Eskimo, among whom it occurs, but infrequently.