We have already noted the fact that men are as a rule four or five inches taller than women. In determining the greater stature of the male it is possible that the sexual organs may have a powerful influence. It is now known that sexual organs have not only the duty of renewing the race,—but have also, by a secretion thrown into the circulation, an influence on the nutrition, well-being and growth of the body. We have only to look at domesticated animals and note the difference between the ox and the bull to see how deep-rooted the influence of the genital glands can be in shaping the size and form of the body. If we study the growth of children it becomes very apparent that the sexual organs play a large part in regulating the rate of development. Between birth and the twentieth year there are two spurts of growth. The first takes place during the first and second year—until the child learns to walk ; in that period the stature shoots up from twenty inches to thirty-three or thirty-four inches—at a rate of about seven inches a year. Thereafter the increase is at the rate of about two and a half inches yearly until the age of puberty approaches and then the second spurt occurs. In Great Britain girls grow more rapidly than boys between the ages of ten and fifteen, and for two or three years are actually taller than boys of their own age. They are more precocious in their growth than boys. The thirteenth year is the one of most rapid growth in girls, whereas in boys it is the sixteenth. Between his fourteenth and sixteenth year a boy usually shoots up about eight inches. We know that at these later periods of rapid growth in the two sexes, the sexual glands are also undergoing a maturing change in structure and function, and we have good reason to suppose that the extra growth is directly due to a secretion these are supplying to the circulation. We thus see that our stature and our bodily growth are determined or at least regulated by a series of glands which exert an influence through their secretions.
Our stature and growth also depend on food, exercise and fresh air; there can be no doubt of that. It is well known that boys of well-to-do people at good schools are taller, heavier, and stronger than boys of poor people in schools situated within the slums of big cities. How much of the difference is due to food and environment and how much is the result of heredity, it is difficult to say, for the better-off class in England is taller than the poorest class. Children naturally inherit stature as well as other features of their parents. The stature of English soldiers is 1,701 mm.1; Oxford undergraduates, however, are 1,726 mm.—an inch taller, and those measured were not fully grown. A group of Scotch soldiers measured 1,718 mm.; a group of Irish, 1,707, of Germans, 1,696, of Italians, 1,620 mm. and the soldier of the United States, 1,786 mm. The various races of European origin have a wonderfully uniform mean stature; 5 feet 6 inches may be accepted as the mean stature of the average European man ; the mean in some countries, such as Italy, falls to nearly two inches below the mean, while in another, such as Scotland, it rises about that amount above the mean.
As we survey the skeletons of the various races of the world which have been collected in the Hunterian Museum, it becomes very apparent that it is amongst the negro and negroid races that the greatest fluctuation in stature is found. The late Dr. MacTier Pirrie, 1 1,700 mm.=5 ft 7 in. 1 in.=254 mm. who lost his life while investigating the negroes of the Sudan, found that the Dinkas, who live in the valley of the White Nile, had a mean stature of 1,801.6 mm.—a fraction under 5 feet 11 inches. The Dinkas are amongst the tallest races in the world. Their lower extremities are remarkably long, making up more than half their height. Where the Sudan merges in the watershed between the Nile and the Congo basins, a negroid tribe—the Akkas —represent one of the smallest if not actually the smallest race of mankind. The men stand about 4 ft. 6 in. high, the women about 4 ft. 2 in. Further south, within the Congo Free State, numerous pygmy races of negroes are found forming settlements and amongst negro tribes of average stature. Still further south, in the region of Cape Colony, another pygmy stock is found—the Bushman race. They are taller than the Akkas, the men measuring 4 ft. 9 in., the women 4 ft. 7 1/4 in. Various pygmy peoples are found scattered in the Far East—in the Andaman Islands, the Malay Peninsula, the Philippine Islands, and in New Guinea. These Eastern pygmies are also negroid races with various features in common with the African pygmies. At first sight it may seem somewhat remarkable that the tallest and the shortest races should be found in the great negro division of mankind. When, however, we remember that stature is regulated by the action of certain glands, it becomes apparent that if the normal action of these regulators of growth is unfixed a double result may be expected—the production of small races on the one hand by under-action and tall races on the other by over-action on the part of the glands. The variability of stature is a characteristic of negro tribes.
At one time the idea gained some support that long ago Europe was inhabited by a pygmy people and that it was from such a race that traditions of elves and fairies had arisen. The basis of this theory was the discovery of bones of people of small stature amongst the graves of a race who lived in Europe when well worked flints were used as cutting and fighting tools. Professor Kollmann, who discovered these bones, thought they indicated the existence of a race of small people, but we now know that these small people formed only a very small proportion of the population to which they belonged.
We have thus made a brief survey of our present knowledge relating to stature. We have seen there is no basis for the belief that we are descended from giants, nor is there any real ground for believing our ancestors were pygmies. Our present size of body appears to be an old character—one which we inherited in common with the great anthropoids. Further we see that our stature is regulated by the action of certain small glands, and that over-action or under-action on the part of these may produce great fluctuations in stature. Dwarfs and giants may arise as sports in any race of mankind. Amongst negro and negroid peoples we see an especial tendency for the production of tall races on the one hand and short or pygmy races on the other.