SOCIAL DIFFERENTIA TION AND INTEGRA TION 729
the subject or slave class an intermediate trading or mercantile class, which ultimately resolved itself into a general business or industrial class. Out of these three primary elements, which may be called the ectoderm, endoderm, and mesoderm, respec- tively, of the social tissues, have been formed what are now known as the "social classes" and the modern social body.
RACE INTEGRATION.
I dismiss this subject, the fundamental theme of sociology, with these few broad strokes, and shall devote the remainder of this paper to a few reflections on what may be regarded as the more especially ethnological aspect of social integration, viz., race integration.
Social differentiation, as we have seen, resulted in a prac- tically unlimited number of races, all socially, and most of them ethnically, distinct. Social integration resulted in the amalga- mation of these heterogeneous races into larger compound mixed races, and these became true races, greatly reducing the number of human races. The attempt to base any important conclusions, therefore, upon differences of race may be said to have utterly failed. All existing races are completely mixed. Some of the elements of which they are composed seem to be distinct and to point to stocks that were once pure, but could such stocks be anywhere found, they, too, would be equally compound and their elements would point back to earlier stocks. There is, however, no possibility now of finding a stock of which this is not true. Ages anterior to any human records nay, ages before man had learned to make anything that archaeolo- gists recognize as a product of art, this process of race amalga- mation had been many times repeated, and the races all inex- tricably blended. All that we see today and call races are simply a few of these composite groups that succeeded in holding together during a considerable period until certain common characteristics had been more or less definitely fixed. But even these race characters were the result of prior synthesis and are equally composite.
The great race distinctions marked by differences in the color
