+437+. In all such cases, however, the absence of records makes the history of the organizations uncertain--we do not know whether or not one of the elements, totemism or exogamy, formerly existed and has yielded to disintegrating influences. Thus local exogamy may have superseded clan exogamy in many places, the former representing the more settled habit of life, and the absence of the totemic constitution may indicate a process of decay of totemism. No general rule for the decision of the question can be laid down--every case must be judged for itself.[788] +438+. Since a custom of exogamy presupposes at least two social groups (clans), and totemism appears to be connected originally with single clans, the natural inference is that the latter has everywhere preceded the former in time. Both have undergone great changes produced by similar sets of circumstances, and in both cases the simplest form is probably the oldest, though here again definite data are lacking. However, comparison of the known exogamous systems points to a two-group arrangement as that from which the existing forms have come. +439+. Exogamy served a good purpose in early stages of society, both by preventing marriages between blood relations and by inducing a sense of the sacredness of the marriage bond. Its long persistence shows that it was regarded by most tribes as necessary for the maintenance of the tribal life. Its restriction of individual freedom in the choice of wives was an evil, and was in time modified and finally thrown off; but it seems to have been the only means, discoverable by early society, by which clans and tribes could live peaceably side by side, and it paved the way for the establishment of the family proper. +440+. This brief account of the most important adjunct of totemism may serve to clear the way for the consideration of the totemic system.