How does this general development of the modes of marriage account for those peculiar laws of exogamy which are universally characteristic of totemic culture, representing strict norms of custom that forbid all marriage except that between specific clans of a tribe, or even only between pairs of totem groups of different clans? Were these marriage ordinances, which have evidently arisen in various places independently of one another, intentionally invented? Or are they the natural outcome of totemic tribal organization, resulting from its inherent conditions, just as did the laws of dual tribal division from the natural growth and partition of the tribes? Now, the forms of totemic exogamy unmistakably constitute a developmental series. In the simplest arrangement, there are no restrictions whatever upon marriage between members of one clan and those of another with which marriage relations exist. Such exogamy, however, is relatively rare in Australia, the land in which the developmental forms of exogamy are chiefly to be found. It seems to be limited to tribes that have merely a dual organization, in which event the clan coincides with one-half the tribe. Even in such cases we find transitions to the next form of exogamy. In this second system, exogamy is restricted to particular totems of the two clans of one and the same tribal division; and, just as in the first case, the children are, as a rule, born directly into the totem group of the mother, or, less commonly, into that of the father. Following this exogamy with direct maternal or paternal descent and undeniably proceeding out of it, we finally have, as the third main form, exogamy with indirect maternal or paternal descent. In this form of exogamy, as in the preceding ones, the children belong to the totem of the mother or to that of the father so far as birth is concerned; as respects their exogamous totem relation, however, they pass over into another totem of the same clan. Thus, birth-totem and marriage-totem are here distinct, and every member of a group belongs to two totems that differ in significance. Now, in the case of a marriage by capture in which the individuals belong to different clans, the question of the totem does not enter. When, therefore, this mode of marriage remains undisturbed by further conditions, we have exogamy of the first form. When a suitor seeks to win the favour of the clan by means of a gift presented to the parents or the kin, marriage by capture passes over directly and without further change into the simple marriage by purchase. The two more exclusive forms of exogamy, on the other hand, are obviously connected with the rise of totemism; they are the result both of the clan divisions which follow from tribal partition and of the accompanying separation into totem groups. The question, therefore, concerning the development of these forms of exogamy, dependent as they are both upon clan divisions and upon totem groups, is essentially