And this theory not only applies to the physiognomy but to the body as a whole. Variations of stature are known to be fewer among savage than civilized people,1 a fact explainable in part by the law of natural selection, and partly by a savage unity of idea in reference to standard, which civilization tends to greatly diversify. Uniformity of condition, also, may, as has been suggested,1 influence, to some appreciable extent, this similarity of stature among savages. People whose food, air, occupation and pastimes are the same, can hardly be expected to present any marked differences of physical development; but that such differences do exist under different conditions of daily life, is demonstrated by the fact, first noticed by Quetelet, that there is not only a difference in stature between inhabitants of cities and of the country, but between members of different professions.3
There are also deviations from the national type caused by disease, which, under long-continued processes of transmission, may easily become permanent, although the natural tendency is fortunately towards extinction in such cases. Certain kinds of constitution, by long usage, become adapted to certain forms of environment, and climatic conditions, and in the fierce struggle for existence which humanity constantly presents, types of strength, rather than beauty, are most likely to prevail. Indeed the latter, being closely allied to effeminacy, when it develops in man, having no sexual quality to sustain or perpetuate it, must yield inevitably to the processes of selection everywhere operative.
Geoffroy has very interestingly pointed out1 that persons who deviate markedly from a common standard of stature, either dwarfs or giants, are as a rule abnormal in other respects, also; being usually deficient both in intelligence and the power of reproduction. It is a matter of every-day observation that enormously large men have usually small or no families; as is the case also with unusually large women; while the greatest fecundity seems to prevail among those of medium size. It has also been remarked s that men of great size are not possessed of strength in proportion, and that the greatest proportional degree of muscular power is usually found among dwarfs. The conditions of life in civilized communities may perpetuate and guard, for some time, these abnormal characteristics; but a little reflection will convince us that they would soon perish, where fidelity to a common type prevails, and the principle of selection is enhanced by the savage struggle for existence.