SOCIAL DIFFERENTIA TION AND INTEGRA TION 735
about this time, the continents assumed approximately their present dimen- sions and relations, and that this creature man, breaking over the barriers that formerly hedged him in, was ready to engage in their conquest. The simple, initial, integrate period of his career had now closed, and a period of marvelous expansion supervened (period II).
Spreading gradually into the various continental areas, the incipient human groups, as yet reasonably homogeneous in character, became widely separated. Some were quite completely isolated and went their separate ways, becoming sharply demarcated from the rest. Others less fully isolated continued to intermingle along the margins of the areas occupied, .-o that gradations of characters occur, and in some cases the resulting hybrid peoples have probably occupied separate areas long enough to become well-estab- lished varieties. Three or four groups only became so widely separated and fixed in physical characters that students are agreed to call them separate races, but these comprise the great body of mankind.
The line marking the close of period II stands for the present time, and F, G, H, and I are the races now in evidence. Let us consider what is hap- pening along this line today. The end of the second period the isolated specializing period has come for the races, and changes of a momentous kind are being initiated. Man has spread out and occupied the world, and the resulting isolations and partial isolations on continent and island of peoples having meager artificial means of transportation, have brought about, directly or indirectly, the variations called races ; but the period of group isolation and consequent race specialization is at an end. In the last few hundred years the sea-going ship and the railway have been invented, and the extremes of the world are no farther apart than were the opposite shores of a good-sized island when, a little while ago, all men went afoot. The period of differentiation is closed forever and the period of universal integration is upon us. We do not see how fast these movements are, but contrasted with the changes of earlier days they are as a hurricane compared with the morn- ing zephyr. The continent of America has changed its inhabitants as in the twinkling of an eye, and Asia, Africa, Australia, and the islands of the Pacific are in the throes of race disintegration. Today each man may go two hun- dred and forty times around the world in his short lifetime. A single indi- vidual may be the parent of progeny in every important land area of the world; and this is only the beginning the first few hundred years of a period to which millions must be assigned. Then how shall we project the lines of the diagram into the future ? There can be but one answer.
Very briefly we may outline the inevitable course of human history. In period III the races will fade out and disappear as the combined result of miscegenation and the blotting out of the weaker branches. The world will be filled to overflowing with a generalized race in which the dominating blood will be that of the race that today has the strongest claim physically and intellectually to take possession of all the resources of the land and the sea.
