does select those who are adapted to it. It is said to favor the Mediterranean race in competition with the Nordic, so that mixed city populations tend to become more brunette, the Nordic strains dying out. How well this claim has been established statistically is open to question; but there can be no doubt that the Jewish race is an example of urban selection. It has withstood centuries of city life, usually under the most severe conditions, in ghettoes, and has survived and maintained a high average of mentality.
Until recently it has been impossible, because of the defective registration of vital statistics in the United States, to get figures which show the extent of the problem of urban sterilization. But Dr. Gillette has obtained evidence along several indirect lines, and is convinced that his figures are not far from the truth.58 They show the difference to be very large and