EVOLUTION OF SOCIAL STRUCTURES 599
an important function. All institutions undergo great modifica- tions and some are completely transformed with time.
The case considered is that of the union of two primitive groups which occupied at the outset the same social position, and that the lowest known. It may be called a case of simple social assimilation. That there have been many such cases there is no doubt, but no such could be observed by enlightened man, for the simple reason that no such primitive groups exist, or have existed since there have been enlightened men. This may sound strange when we constantly hear of existing hordes and clans. But I make bold to affirm that none of the hordes or clans now existing are at all primitive. Nay, I go farther and maintain that all hordes and clans, all tribes, and all races are equally old. The lowest race on the earth is as old as the most enlightened nation. There is no escape from this except in the old exploded theological doctrine of special creation. The theory of polyge- nism is a form of that doctrine applied to human races. To admit it involves the surrender of the whole doctrine of evolution. If man has evolved from a lower prehuman stage, he emerged as man at a given time, and all human races have descended from that one truly primitive type. All human races are therefore equally old. The differences among them are not at all due to the time it has required to reach their present state, because all have had the same time in which to do this. The differences are wholly due to the different conditions under which they have been placed and in conformity with which they have developed.
There has, of course, been a great variety of influences at work in determining the direction and degree of development of the races of men, but there is one element that has had more to do with this than any other, or perhaps than all others combined ; that is the element with which we have been dealing, viz., the element of social assimilation. When we realize that all human races are equally old, we can readily see that all cases of simple assimilation, such as the one sketched, must have occurred far back in the early history of man. The period of social differentia- tion may have been very long. It may have occupied half of the two hundred thousand years that are commonly assigned to man
