large as they now are, will repeat the history of the American Indian lands, a history of gradual shrinkage and disappearance as territorial entities. [Sidenote: Contrasted location.] Every land contains in close juxtaposition areas of sharply contrasted cultural, economic and political development, due to the influence of diverse natural locations emphasizing lines of ethnic cleavage made perhaps by some great historical struggle. In mountainous countries the conquered people withdraw to the less accessible heights and leave the fertile valleys to the victorious intruders. The two races are thus held apart, and the difference in their respective modes of life forced upon them by contrasted geographic conditions tends still farther for a time to accentuate their diversity. The contrasted location of the dislodged Alpine race, surviving in all the mountains and highlands of western Europe over against the Teutonic victors settled in the plains,[281] has its parallel in many parts of Asia and Africa; it is almost always coupled with a corresponding contrast in mode of life, which is at least in part geographically determined. In Algeria, the Arab conquerors, who form the larger part of the population, are found in the plains where they live the life of nomads in their tents; the Berbers, who were the original inhabitants, driven back into the fastnesses of the Atlas ranges, form now an industrious, sedentary farmer class, living in stone houses, raising stock, and tilling their fields as if they were market gardeners.[282] In the Andean states of South America, the eastern slopes of the Cordilleras, which are densely forested owing to their position in the course of the trade-winds, harbor wild, nomadic tribes of hunting and fishing Indians who differ in stock and culture from the Inca Indians settled in the drier Andean basins.[283] [See map page 101.] [Sidenote: Geographical polarity.]