The historical relations of the marriage classes--of which there are found as many as eight in some tribes--are quite unexplained. We only see that these arrangements seek to attain the same object as the totem exogamy, and even strive for more. But whereas the totem exogamy makes the impression of a sacred statute which sprang into existence, no one knows how, and is therefore a custom, the complicated institutions of the marriage classes, with their sub-divisions and the conditions attached to them, seem to spring from legislation with a definite aim in view. They have perhaps taken up afresh the task of incest prohibition because the influence of the totem was on the wane. And while the totem system is, as we know, the basis of all other social obligations and moral restrictions of the tribe, the importance of the phratries generally ceases when the regulation of the marriage choice at which they aimed has been accomplished. In the further development of the classification of the marriage system there seems to be a tendency to go beyond the prevention of natural and group incest, and to prohibit marriage between more distant group relations, in a manner similar to the Catholic church, which extended the marriage prohibitions always in force for brother and sisters, to cousins, and invented for them the grades of spiritual kinship[16]. It would hardly serve our purpose to go into the extraordinarily intricate and unsettled discussion concerning the origin and significance of the marriage classes, or to go more deeply into their relation to totemism. It is sufficient for our purposes to point out the great care expended by the Australians as well as by other savage people to prevent incest[17]. We must say that these savages are even more sensitive to incest than we, perhaps because they are more subject to temptations than we are, and hence require more extensive protection against it. But the incest dread of these races does not content itself with the creation of the institutions described, which, in the main, seem to be directed against group incest. We must add a series of ‘customs’ which watch over the individual behaviour to near relatives in our sense, which are maintained with almost religious severity and of whose object there can hardly be any doubt. These customs or custom prohibitions may be called ‘avoidances’. They spread far beyond the Australian totem races. But here again I must ask the reader to be content with a fragmentary excerpt from the abundant material.