THE SIGNIFICANCE OF A FALLING BIRTH-RATE

would appear, the marriage-rate, the birth-rate, and, it may be added, the death-rate are all alike high. Karl Ranke has investigated the question with considerable care among the Trumai and Nahuqua Indians of Central Brazil.³⁵ These tribes are yet totally uncontaminated by contact with European influences; consumption and syphilis are alike unknown. In the two villages he investigated in detail, Ranke found that every man over twenty-five years of age was married, and that the only unmarried woman he discovered was feeble-minded. The average size of the families of those women who were over forty years of age was between five and six children, while, on the other hand, the mortality among children was great, and a relatively small proportion of the population reached old age. We see therefore that, among these fairly typical savages, living under simple natural conditions, the fertility of the women is as high as it is among all but the most prolific of European peoples; while, in striking contrast with European peoples, among whom a large percentage of the population never marry, and of those who do, many have no children, practically every man and woman both marries and produces children.