[25] The Dangerous Age, London, 1912.
[26] See W. L. Comfort’s Midstream for the same crisis in men (1914).
[27] The Salvaging of Civilization: The Probable Future of Mankind, New York, 1921. 199 p.
[28] The Old World in the New, 1914, p. 27.
[29] The Longevity of Birds.
[30] On the Comparative Longevity of Man and Animals, 1870.
[31] Men of the Old Stone Age, New York, 1915, p. 40.
[32] See my “What We Owe to the Tree-life of Our Ape-like Ancestors,” Ped. Sem., 23:94–116, 1916.
[33] Adolescence, Ch. XIII, “Savage Pubic Initiations,” etc.
[34] Primitive Folk, p. 42.