On the other hand, it has been my good fortune to be able to demonstrate the existence of a direct influence of environment upon the bodily form of man by a comparison of immigrants born in Europe and their descendants born in New York City (Boas). I have investigated four groups of people,—the South Italians, representing the Mediterranean type of Europe, which is characterized by short stature, elongated head, dark complexion and hair; the Central European type, which is characterized by medium stature, short head, light hair and lighter complexion; the Northwest European type, which is characterized by tall stature, elongated head, light complexion, and blond hair. Furthermore, I have investigated an extended series of East European Hebrews, who resemble in some respects the Central European group. The traits which I selected for examination are head-measurements, stature, weight, and hair-color. Among these, only stature and weight are closely related to the rate of growth, while head-measurements and hair-color are only slightly subjected to these influences. Differences in hair-color and head-development do not belong to the group of measurements of which I spoke before, which depend in their final values upon the physiological conditions during the period of growth. From all we know, they are primarily dependent upon heredity. The results of our inquiry have led to the unexpected result that the American-born descendants of these types differ from their parents; and that these differences develop in early childhood, and persist throughout life. It is furthermore remarkable that each type changes in a peculiar way. The head of the American-born Sicilian becomes rounder than that of the foreign-born. This is due to a loss in length and an increase in width. The face becomes narrower, the stature and weight decrease. The head of the American-born Central European loses both in length and width, more so in width, and thus becomes more elongated. The face decreases very much in width; stature and weight increase. The modifications of the American-born descendants of the Scotch type are not marked, except that stature and weight increase. The American-born Hebrew has a longer and narrower head than the European-born; the head is therefore considerably more elongated. His face is narrower; stature and weight are increased. In none of the types have marked differences in color of hair between American-born and foreign-born been found.