I must however note, in the first place, that as I have stated the case, exogamy and totemism appear as two separate and distinct elements, whereas it is usual to consider exogamy as an essential part of totemism. I cannot, however, see that this is so. In advanced totemism, it is true, they are found as inseparable parts of one system, but they may well have started separately and coalesced later. In point of fact, all the evidence points in this direction, and if we cease to consider exogamy as a necessary element of totemism, we can advance investigation more rapidly and with greater accuracy. We come very quickly upon what may be termed natural exogamy. Male working with male outside the groups formed by women and the younger offspring would produce a natural exogamy, which would have followed upon the exogamy produced by hostile capture of women, and two streams of influence would thus tell in favour of the evolution of a system of formal exogamy, and Dr. Westermarck's theory of a natural avoidance of housemates, with all its wealth of evidence, helps us at this point. The position is not so clear as to totemism. If we begin, however, with a clear understanding that it is not a part of the machinery of exogamous grouping, but an independent growth of its own, we shall have gained an important point, for the contrary opinion has very often obscured the issue and prevented research in the right direction. It will be advisable to have before us the principal theories as to the origin of totemism. There are practically three--Mr. Frazer's, Mr. Lang's, and Mr. Baldwin Spencer's. Mr. Frazer considers totemism to be "in its essence nothing more or less than an early theory of conception, which presented itself to savage man at a time when he was still ignorant of the true cause of the propagation of the species." Mr. Frazer explains this theory further by saying that "naturally enough, when she is first aware of the mysterious movement within her, the mother fancies that something has that very moment passed into her body, and it is equally natural that in her attempt to ascertain what the thing is, she should fix upon some object that happened to be near her, or to engage her attention at the critical moment."[356]