by a tendency to more or less permanent mating. Once the reasoning powers of early mankind had evolved to a certain point, the advantage of organization may have forced itself upon atten- tion ; and a tendency to permanent mating would have accelerated, if it were not one of the prime factors in forcing, the consideration of the subject. Directly the momentary impulses of promiscuity began to yield to the desire for more or less durable possession, — that is to say, directly the rude beginnings of marriage made their appearance, — regulation became a necessity, if only to prevent un- ceasing strife and the breaking up of the inchoate community. The division of a horde into two exogamic moieties may have presented itself as the most obvious course. Each of these moieties may have comprised one portion of the mothers of the horde with their children. If each moiety had been made endo- gamous the result would have been not organization, but separation. The horde would have split, as doubtless it had done many times already. This would not have been regulation ; it would not have been advance. Society would have been exactly where it was before. But by providing that each moiety should mate with the other, the two moieties would have been kept together; the horde would have taken the first step in organization, a step destined ultimately to bind its members together into a tribe with a con- sciousness of unity which even the possession of a common tongue had not given it. Of course experience would gradually show that by itself this division was not enough to effect all the objects desirable. It would, for example, effect the prohibition of unions between mother and son and between brother and sister, but not between father and daughter. It was a first step only ; as the consciousness of kinship developed, it would bring further changes sooner or later in its train.
Such voluntary fission is as a fact not very uncommon in a low stage of savagery. Though my attention has only been directed to it within the last few months, and though I have made no special research on the subject, I have by accident come across a number of examples. With the arguments of Messrs. Spencer and Gillen in favour of the voluntary origin of changes in the organiza- tion and ceremonies of the tribes of Central Australia we are all familiar. Those arguments have recently been elaborated in their