valley of the Indus to the coasts of Asia Minor a region decreasing in elevation as it passes from the mountainous uplift looking down upon the Indus to the plateau of Iranistan, and so on to the broken ranges in which the Tigris and Euphrates have their mountain originfurnishes continuous climatic conditions. In its culture, the mountainous region has varied yet it has kept somewhat similar culture conditions, while the plain and rivers below, toward the Persian Gulf and the Indian Ocean, have as constantly furnished the development of commerce and cultivation. Considered with reference to climate, therefore, the region which we are considering again appears as a link region, lying between the climatic conditions which exist over the Sahara and Arabia and those which obtain in the Eurasian plains from the Vistula to the Asian uplift. Nor is it without its close connection with the various history that has there appeared that this region has in Asia Minor a climate at so many points closely resembling that of the high interior of Asia, so that from western Asia Minor to the north of eastern Tibet the same Turkish language may are to be found in the valleys of Morocco and Baluchistan, of Afghanistan and the Iberian peninsula. Over this entire region closely similar deciduous trees and annuals almost as similar flourish. Over them, consequently, the same agriculture is possible. As will be seen, in Supan's distribution of floral kingdoms, this floral region which abuts to the north in Europe on the flora of the great forest, of which so few remnants are left, between the North Sea and the Sea of Okhotsk, which touches on the east upon the flora of inner Asia, and which is flanked to the south by the typical flora of Africa, Madagascar, and India—at so many points furnishing the proof of an earlier connection-constitutes a connecting link in limitations of precipitation, climate, and vegetation which permit substantially similar human culture and ideals to exist over the entire area. Substantially within these limits were felt the influences of the earlier empires from the fourth to the first millennium before Christ. Within them swayed the refluent tides of the successive empires in the first millennium before and the first millennium after Christ, beginning with the Persian expansion and ending with that of Islam. This region, therefore, in which nearly all Eurasian fruits and so large a share of the food plants of civilization were first cultivated, in this respect is again seen to be a connecting link between the rice and wheat civilizations of Asia and the wheat civilizations of Europe. SOUTHWESTERN ASIA AS A DIKE If we now collate these facts with reference to elevations and return again to the distribution of levels with which we began, it becomes plain that what we are really considering in these varying conditions is the fact that the Great Uplift is really, in the region which we are discussing, a narrow dike of mountains between the comparatively flat lands which extend from Arabia to the Atlantic, which we know as the Saharan region, and the other great flat area which abuts on the northern edge of the inclosed region we have already mentioned, and extends from the western boundary of Russia to eastern Siberia. This strip, which one might almost term, borrowing a physiological analogy, connective tissue between the developed regions in India and China and those of Europe, is in the last analysis a sort of mountain rampart which separates the flat lands of central Asia, with one definite type, from the flat lands of Africa and Arabia, with another type as definite. This rampart is also so situated with reference to atmospheric currents that it carries along the conditions, so far as human life is concerned, which exist along the northern edge of the Mediterranean. RACIAL DISTRIBUTION The effect of this upon human life first appears in race. The races of men are in general terms distributed in the eastern hemisphere in three great masses: the yellow race occupies eastern Asia, holding the region which has already been clearly indicated as the flat lands of northern Asia, its central uplift, and its eastern coast; the white race in its various forms extends from India, connected by the tract we are considering with white expansion in Europe, Arabia, and North Africa, and the black race holds two-thirds of the African continent. This general distribution sufficiently indicates the fashion in which southwestern Asia has given the bridge, whatever theory we adopt as to the origin of the Aryan race, either that the race left India and spread over Europe and the Mediterranean basin, or starting in Europe has found. its way into India, occupying that peninsula until it reached in Indo-Asia and the inner inclosed basin of the con A L CHER tinent the tenacious boundaries of the yellow race. These have remained substantially unaltered from the earliest gleams of race relations. similar tenacious boundary exists in the African continent, following closely, though not absolutely, since this itself indicates a physiographic condition, the southern line of the date palm and the northern line of the banana. But when we adopt a closer scrutiny of races, as in the map, page 264, in which the chief effort has been to indicate the interrelation of the races, whose wider arrangement has been already portrayed, we discover that the bridge of which we have spoken constitutes the one region in which there has been a confused admixture of the various types which exist north and south of the Mediterranean and north and south of the Himalayan uplift, north and south, in short, of the great depression which divides Europe from Africa and the great elevation which divides northern from southern Eurasia. On southwestern Asia have flowed from the north the tides of the nomad life in the great plains, which extend without a break from northeastern Siberia to the INDISCHER OCEAN WHITE > YELLOW BLACK ILLER The Races of Mankind Before the European Invasion Caucasus and the Ural. Against it have flowed from the south the Berber and Arab tribes, Hamitic and Semitic, and in some places, as in the inclosed basins of Asia Minor and the basin, once as closed, though now opened, of the Hungarian plains, congeners of the yellow races have forced their way. In a long, detached, straggling line the white races hold a slender pathway from their great mass in Europe to their great mass in India. Each of these divisions guided men by the culture developed in their native region, feeling their way along the parts of that diversified region be tween the plains about the Sea of Aral and the plains about the Red Sea, together with the Aryan entrance from east or west, to whatever parts of this tract best suit the culture which each has developed in its own home. FAUNAL DIVISIONS What is true of this linked relation is true also of the fauna. This elevated tract between the plains of Arabia to the south and the plains of Tartary to the north, with its coterminous conditions of rainfall, climate, and flora, carries analogous animal conditions across the Eurasian mass from east to west. The roe deer among the Cervidæ, representing in size, in agility, and in a more graceful outline the gradual change from the bulkier forms of the northern species of the deer to the more slender outlines of the antelope, is found upon the Pacific coast in north China and in another extended habitat over Europe. These |