tiers encountered in Europe were either not present at all in Asia or else were too weak to offer substantial resistance. Hence Russia has in the last 100 years pushed out to the confines of India and China and added millions of square miles to her territory beyond the Caspian and in southern Siberia. In one place, she has even gone beyond what would appear as the normal physical boundary: in the conquest of the trans-Caucasus she has begun a march that points to the Persian Gulf as her ultimate goal.
Turning now to the more intimate relation of the great Russian plain to the people who have made it their own, a number of striking facts appear. In the first place, it has produced and preserved for the whole vast central area a common physical type, a common religion and a common language. The 125 million Russians occupying this central territory of the Russian plain, as has been often pointed out, show a truly astounding uniformity of head formation when one takes into consideration the size of the territory and the number of people involved. The variation in cephalic index, according to ethnologists, is only about 5 points around 82. That is to say, the Russian not only belongs to the round-headed type, but the ratio between the length and the width of head among the 125 millions varies astonishingly little when compared with the variation in the cephalic index in races whose habits and environment show greater variety. Among the Italians, for example, it is as high as 14 instead of 5 as in Russia, and in France it is 10. Yet both the territory and the number of people involved in each case is very much smaller. A further point of some interest is the fact that Slavic skulls thirteen centuries old, found in this region, exhibit the same peculiarity. Evidently the absorption of the Varangians, and later, of the Turco-Finnish tribes of the region, has in no way affected the head formation. The power of the great plain is dominant and the uniformity and monotony of the land reflects itself in an unparalleled extension over a vast area of a uniform type of head formation.
It would be a mistake, however, to leave the impression that, since a common head formation prevails among the Russians, they are alike in other respects. Quite apart from the many alien races on the frontier, there are three main groups among the Russians themselves, differing from one another not only in dialects, habits and disposition, but physically as well.
First there are the Great Russians numbering over 82,000,000 and much the largest of the three groups. They occupy the heart of Russia with Moscow as the center. Second is the Little Russian, about 37,000,000 strong. He holds the territory south and southwest, including the Don Cossacks, and his center is at the old and first capital of the Russians, on the Dnieper at Kiev. Third is the White Russian, about 5,000,000 in number, in lands east of Poland and northward around Lithua-
