[90] Eugenics Record Office, Bulletin No. 10 A, The Scope of the Committee's Work, Cold Spring Harbor, L. I., Feb., 1914; No. 10 B, The Legal, Legislative and Administrative Aspects of Sterilization, same date.
[91] Eugenics Record Office Bulletin No. 9: State Laws Limiting Marriage Selection Examined in the Light of Eugenics. Cold Spring Harbor, L. I., June, 1913.
[92] Penrose, Clement A., Sanitary Conditions in the Bahama Islands, Geographical Society of Baltimore, 1905.
[93] See von. Gruber and Rüdin, Fortpflanzung, Vererbung, Rassenhygiene, p. 169, München, 1911.
[94] Davenport, Charles B., Heredity in Relation to Eugenics, pp. 184 ff., New York, 1911.
[95] Harris, J. Arthur, "Assortative Mating in Man," Popular Science Monthly, LXXX, pp. 476-493, May, 1912. The most important studies on the subject are cited by Dr. Harris.
[96] An interesting and critical treatment of sexual selection is given by Vernon L. Kellogg in Darwinism To-day, pp. 106-128 (New York, 1908). Darwin's own discussion (The Descent of Man) is still very well worth reading, if the reader is on his guard. The best general treatment of the theory of sexual selection, especially as it applies to man, is in chapter XI of Karl Pearson's Grammar of Science (2d ed., London, 1900).
[97] Diffloth, Paul, Le Fin de L'Enigme, Paris, 1907.
[98] The best popular yet scientific treatment of the subject we have seen is The Dynamic of Manhood, a book recently written by Luther H. Gulick for the Young Men's Christian Association (New York, The Association Press, 1917).
[99] The sympathy which we mentioned as the beginning of the hypothetical love affair does lead to a partial identity of will, it is true; but there is often too little in common between the man and woman to make this identity at all complete. As Karl Pearson points out, it is almost essential to a successful marriage that two people have sympathy with each other's aims and a considerable degree of similarity in habits. If such a bond is lacking, the bond of sympathy aroused by some trivial circumstance will not be sufficient to keep the marriage from shipwreck. The occasional altruism of young men who marry inferior girls because they "feel sorry for them" is not praiseworthy.