They have a poorly developed lower face, and breathe through the mouth. The lowland races are doubtless the older type and represent the primitive characteristics of men. At some point an isolation occurred, possibly with the pushing up of the great plateau of Central Asia and the formation of dry desert uplands. An oasis or an isolated upland valley would combine, both in food and climate, the elements on which the formation of the more vigorous type depended. Later comes the renewal contact with the lowland races and the descent of the northern nomad to the fertile lowlands as a conqueror. From this union come the mixed races that occupy the medium altitudes. The upland races can not go too far down south without facing extinction, while the lowland races have been unsuccessful in facing the rigor of dry, cold uplands.
I shall call the pure uplander the long-faced type, the pure lowlander the round-faced type, and the mixture of the two, the oval-faced type. I use this contrast not because it is the only one that might be selected, but because it permits of a threefold division more readily then the others. An additional reason is that the round-faced and the longfaced women are now popular contrasts. The frontispieces of magazines give us the round-faced girl as the approved type of female beauty, while the suffragette, the old maid, the intellectual woman and the freak are pictured with long faces and protruding jaws. The difference, however, is not merely in the skull and the bony structures of the face. Even more marked is the contrast between the placid plumpness of the round face and the nervous make-up of the long face. Like differences are observed in man, and they give a ready means by which the two types can be distinguished.
In the application of current biologic theories to the human race, we must face the fact that there are two points or centers of elimination. As the race moves down or into hot countries, the upland type or the mixed type in which it is dominant is eliminated, while an upward movement, or one into cold dry regions tends to weed out the lowland type and the elements that it has given to mixed breeds. Changes in food and drink create a like and, at the present time, a more prominent tendency in these directions. Diseases also contribute their share towards this double elimination. Some, like tuberculosis, work against the upland type, while the fevers and alcohol weed out the lowlanders. The action of this double elimination can be shown by using the Mendelian law of crosses. When parents of mixed breeds unite, the children are one fourth pure of each pure type and one half of the mixed type. If none of the pure types survived, the next generation, being children of the mixed type, would again be one fourth of each of the pure types and one half of the mixed type. In each generation the pure breeds might be eliminated, and yet one fourth of the children of mixed parentage would be representatives of each pure type. Elimination