It is objected that if the long-lived marry each other, the short-lived will also marry each other and thus the race will gain no more than it loses. The reply to this is that the short-lived will marry in fewer numbers, as some of them die prematurely; that they will have fewer children; and that these children in turn will tend to die young. Thus the short-lived strains will gradually run out, while the long-lived strains are disseminated.
CHAPTER XII
Hankins, F. H., "The Declining Birth-Rate," Journal of Heredity, V, pp. 36-39, August, 1914.
Smith, Mary Roberts, "Statistics of College and Non-college Women," Quarterly Pubs. of the American Statistical Assn., VII, p. 1 ff., 1900.
"Statistics of Eminent Women," Pop. Sci. Mo., June, 1913.
"Marriage of College Women," Century Magazine, Oct., 1895.
Blumer, J. O., in Journal of Heredity, VIII, p. 217, May, 1917.
The statistics of this and the following middle west universities were presented by Paul Popenoe in the Journal of Heredity, VIII, pp. 43-45.