Again, Professor Kohler has expressed his belief in the explanation that exogamy was an early method of political self-preservation.[1888] That intermarriage is valuable from a political point of view, and has often taken place in order to increase intertribal or international friendship, is beyond doubt.[1889] But it is another question whether the strictly prohibitive exogamous rules, the infringement of which is considered a most heinous crime, can be accounted for in this way. It is worth noticing that not only marriage, but also less regular connections between members of the same exogamous group are held in horror. The Australians, for instance, consider cohabitation between individuals belonging to clans that cannot intermarry not less criminal than marriage, often punishing such unions with death.[1890] Among the Melanesians, says Dr. Codrington, “intercourse within the limit which restrains from marriage, where two members of the same division are concerned, is a crime, is incest.”[1891] Holm makes a similar observation on the prohibited degrees among the Eastern Greenlanders.[1892] Speaking of the Samoans, Mr. Prichard remarks, “Of all their customs, the most strictly observed, perhaps, was that which forbade the remotest reference to anything, even by way of a joke, that conveyed the slightest indelicacy in thought or word or gesture, when brothers and sisters were together. In presence of his sister, the wildest rake was always modest and moral. In presence of her brother, the most accommodating _coquette_ was always chaste and reserved. This custom remains intact to the present day.”[1893] Dr. Tylor remarks that anthropologists have long had before them the problem of determining how far clan-exogamy may have been the origin of the prohibited degrees in matrimony.[1894] But we have seen that it is practically impossible to trace any distinct limit between these two sets of rules; hence they seem to be fundamentally identical—a conclusion in which most anthropologists agree. And the prohibitions of close intermarriage certainly cannot be explained as a “method of political self-preservation.”