Page:Popular Science Monthly Volume 75.djvu/599

Rh mixed with Celtic elements, forms the rural population of the United States, while the greater portion of the population of the larger and largest cities is composed of the new immigration. It is a bold assumption that the United States is a "melting-pot" in which all the races of Europe are fused to a new race. A general intermixture of the old and the new immigrants can take place only in the large cities while the rural population, the backbone of the nation, will not be appreciably affected. This mixed city population will not persist for any length of time. It is a generally recognized fact that city populations have much less vitality than the agricultural classes. But the surprisingly rapid rate at which families in the cities die out was not known until the remarkable observations of Hansen, Amnion and others were made public.

In modern times the causes which contribute to the rapid destruction of the city population are much more potent than in the past. The cities are generally much larger and it is certain that the healthfulness of a city decreases as its size increases. It is true that sanitary measures are much more efficient than in former times, but it is also true that the destructive influences have grown in strength and new ones have appeared. The modern factory work, the poor housing conditions of the lower classes, tend to destroy life and weaken vitality. Race suicide is practised especially in the cities, while it is almost unknown among the country population. The struggle for existence is much severer in the cities; marriages are fewer; the mortality of children is greater. Prostitution, the curse of large cities, is an enemy to marriage and tends to shorten and destroy life by transmitting and spreading venereal diseases. To all this we must add the attractions of city life, the chase after pleasure, the constant excitement, the nervous strain, which are all hostile to the vitality of families. Another cause of the rapid extinction of the city population lies in the very mixture of so many races. There is a biological law that hybrids do not tend to reproduce their kind. The fecundity of such a mixed population is appreciably lower than that of a pure race. Lapouge found that in those regions of France where the brachycephalic Alpine race has preserved a comparative purity the birth rate is much higher than in the districts where the race is greatly mixed with Teutonic blood. In the latter regions the birth rate is actually decreasing.

It is evident that the lower classes, living under less favorable conditions than the well-to-do, are more subject to rapid extinction. But