to swell the other middle classes; or else, entirely worsted in the struggle, land in a generation or two in the lowest ranks of all. Thus a continual tide of migration becomes necessary to insure stability in numbers in the entire population. This ingenious scheme, too simple of course to be entirely correct, as Giddings has suggestively pointed out,[1] does nevertheless contain a germ of truth. Our problem is to test its applicability to modern conditions by a study of purely anthropological facts.
The first physical characteristic of urban populations, as compared with those of country districts, which we have to note, is their tendency toward that elongated shape of head which is characteristic of two of our principal racial types, the Teutonic and the Mediterranean respectively.
It seems as if for some reason the broad-headed Alpine race was distinctly a rural type. This we might have expected from the persistency with which it clings, as we have seen, all over Europe, to the mountainous or otherwise isolated areas. Thirty years ago an observer in the ethnically Alpine district of south central France noted an appreciable difference between town and country in the head form of the people.[2] In a half dozen of the smaller cities his observations pointed to a greater prevalence of the long-headed type than in the country round about. In the same year, in the city of Modena in Italy, investigations of the town and country populations, instituted for entirely different purposes, brought the same peculiarity to light.[3] These facts escaped notice, however, for about a quarter of a century. In entire ignorance of them, in 1889, a gifted young professor in the university at Montpellier in southern France, having for some years been occupied in outlining various theories of social selection, stumbled upon a surprising natural phenomenon.[4] On examination of a considerable series of skulls, dating from various periods in the last two hundred years, which had been preserved in crypts at Montpellier, he found that the upper classes, as compared with the plebeian population, contained a much larger percentage of long-headed crania. These crania of the aristocracy, in other words, seemed to conform much more nearly to the head form of the Teutonic race than those of the common people. Additional interest was awakened in the following year by the researches of Dr. Ammon, of Carlsruhe, who, working again in entire independence upon measurements of thousands of conscripts of the Grand Duchy of Baden, discovered radical differences