accept as a second factor in the situation, therefore, the inherent
selfishness in human nature which is not willing to be burdened with the
care of children. In other countries, and apparently in all ages, the
wealthy have been characterized by smaller families than the poor. The
following table from Bertillon, [Footnote: Quoted by Newsholme, Vital
Statistics, p. 75.] showing the number of births per thousand women
between fifteen and fifty years of age in Paris, Berlin, and London
among the various economic classes, shows conclusively that it is not
altogether the pressure of economic wants which leads to the limiting of
a population:


BIRTHS PER THOUSAND WOMEN PER ANNUM

Paris Berlin London.

Very poor ....... 108 157 147
Poor ............ 95 129 140
Comfortable ..... 72 114 107
Rich ............ 53 63 87
Very rich ....... 34 47 63


(3) Besides economic conditions and individual selfishness we must
unfortunately add another cause of decreasing birth rate in our
population which has been definitely ascertained, and that is vice. Vice
cuts the birth rate chiefly through the diseases which accompany it.
About 20 per cent of American marriages are childless, and medical
authorities state that in one half of these childless marriages the
barrenness is due to venereal diseases. According to Dr. Prince A.