Page:Popular Science Monthly Volume 51.djvu/27

Rh land pony and the Percheron horse are likewise classified together. These abnormities are, to be sure, partly the result of artificial selection by man; but the same variation holds to a considerable extent among the wild animals.

The bodily height of a group of men is the resultant of a number of factors, many of which are as purely artificial as those concerned in the domestication of animals. These causes are quite as truly social or economic as they are physical or physiological. Among them we may count environment, natural or artificial selection, and habits of life. Beneath all of these, more fundamental than any, lies the influence of race which concerns us ultimately. This is overlaid and partially obscured by a fourth peculiarity manifested as a result of the sportiveness of Nature, whereby a large number of variations are due to chance, seemingly not caused by any distinct influences whatever. By scientific analysis we may eliminate this last factor, namely, chance variation. The first four causes besides race are more important and deserve consideration by themselves.

Among savages it is easy to localize the influence of environment, as it acts directly through limitation of the food supply. In general, the extreme statures of the human species are found either in regions where a naturally short race, like the Bushmen of South Africa, are confined within a district of great infertility like the Kalahari Desert; or, on the other hand, where a naturally tall race, like the Polynesians in the Pacific Ocean, enjoys all the material bounties which Nature has to bestow. It is probable that the prevalent shortness of the Eskimo and other inhabitants of the arctic regions is largely due to this factor. It is also likely that the miserable people of Terra del Fuego are much shorter than the Patagonians for the same reason. Scarcity or uncertainty of food limits growth. Wherever the life conditions in this respect become changed, in that place the influence of environment soon makes itself felt in the average stature of the inhabitants. Thus the Hottentots, physically of the same race as the Bushmen, but inhabiting a more fertile region, and, moreover, possessed of a regular food supply in their flocks and herds, are appreciably taller from these causes alone. All the aborigines of America seem to be subject to this same influence of the fertility of their environment. In the Mississippi Valley, for example, they are much taller than in the desert lands of Arizona and New Mexico. In the mountains on either side of the Mississippi basin, they are as a rule distinctly shorter, although living the same life and belonging to the same race. The Creeks and the Iroquois exceed the Pueblos by several inches, probably because of the material bounty of their environment; and where we find a single tribe, such as the Cherokees,