This extension of the field of comparison has nothing about it which is not legitimate. Undoubtedly these people are more advanced than those of Australia. Their civilization has become much more advanced: men there live in houses or under tents, and there are even fortified villages. The size of the society is much greater, and centralization, which is completely lacking in Australia, is beginning to appear there; we find vast confederations, such as that of the Iroquois, under one central authority. Sometimes a complicated system of differentiated classes arranged in a hierarchy is found. However, the essential lines of the social structure remain the same as those in Australia; it is always the organization on a basis of clans. Thus we are not in the presence of two different types, but of two varieties of a single type, which are still very close to each other. They represent two successive moments of a single evolution, so their homogeneousness is still great enough to permit comparisons. Also, these comparisons may have their utility. Just because their civilization is more advanced than that of the Australians, certain phases of the social organization which is common to both can be studied more easily among the first than among the second. As long as men are still making their first steps in the art of expressing their thought, it is not easy for the observer to perceive that which moves them; for there is nothing to translate clearly that which passes in these obscure minds which have only a confused and ephemeral knowledge of themselves. For example, religious symbols then consist only in formless combinations of lines and colours, whose sense it is not easy to divine, as we shall see. There are many gestures and movements by which interior states express themselves; but being essentially ephemeral, they readily elude observation. That is why totemism was discovered earlier in America than in Australia; it was much more visible there, though it held relatively less place in the totality of the religious life. Also, wherever beliefs and institutions do not take a somewhat definite material form, they are more liable to change under the influence of the slightest circumstances, or to become wholly effaced from the memory. Thus the Australian clans frequently have something floating and Protean about them, while the corresponding organization in America has a greater stability and more clearly defined contours. Thus, though American totemism is further removed from its origins than that of Australia, still there are important characteristics of which it has better kept the memory.