Among the Australians the system of _Totemism_ takes the place of all religious and social institutions. Australian tribes are divided into smaller _septs_ or clans, each taking the name of its _totem_. Now what is a totem? As a rule it is an animal, either edible and harmless, or dangerous and feared; more rarely the totem is a plant or a force of nature (rain, water), which stands in a peculiar relation to the whole clan. The totem is first of all the tribal ancestor of the clan, as well as its tutelary spirit and protector; it sends oracles and, though otherwise dangerous, the totem knows and spares its children. The members of a totem are therefore under a sacred obligation not to kill (destroy) their totem, to abstain from eating its meat or from any other enjoyment of it. Any violation of these prohibitions is automatically punished. The character of a totem is inherent not only in a single animal or a single being but in all the members of the species. From time to time festivals are held at which the members of a totem represent or imitate, in ceremonial dances, the movements and characteristics of their totems. The totem is hereditary either through the maternal or the paternal line; (maternal transmission probably always preceded and was only later supplanted by the paternal). The attachment to a totem is the foundation of all the social obligations of an Australian: it extends on the one hand beyond the tribal relationship, and on the other hand it supersedes consanguineous relationship[9]. The totem is not limited to district or to locality; the members of a totem may live separated from one another and on friendly terms with adherents of other totems[10]. And now, finally, we must consider that peculiarity of the totemic system which attracts the interest of the psychoanalyst. Almost everywhere the totem prevails there also exists the law that _the members of the same totem are not allowed to enter into sexual relations with each other; that is, that they cannot marry each other_. This represents the _exogamy_ which is associated with the totem. This sternly maintained prohibition is very remarkable. There is nothing to account for it in anything that we have hitherto learned from the conception of the totem or from any of its attributes; that is, we do not understand how it happened to enter the system of totemism. We are therefore not astonished if some investigators simply assume that at first exogamy--both as to its origin and to its meaning--had nothing to do with totemism, but that it was added to it at some time without any deeper association, when marriage restrictions proved necessary. However that may be, the association of totemism and exogamy exists, and proves to be very strong. Let us elucidate the meaning of this prohibition through further discussion.