[50] The Boy Problem, Educational Pamphlet no. 4, p. 26, of the American Society of Sanitary and Moral Prophylaxis, 105 West 40th Street, New York.
[51] Jane Addams, The Spirit of Youth and the City Streets, p. 20. The Macmillan Company, New York.
[52] Emerson, Education, p. 38. Riverside Monograph Series.
[53] Henry Bryan Binns, Abraham Lincoln, p. 356.
[54] Charles Kingsley, The Roman and the Teuton, p. 46.
[55] Winfield S. Hall, M.D., From Youth into Manhood, p. 32. Association Press, New York.
[56] Hall, Reproduction and Sexual Hygiene.
[57] From an investigation conducted by Dr. Winfield S. Hall.
[58] "A Social Emergency," First Annual Report of the Social Hygiene Society of Portland, Oregon, and the Bulletin of the Oregon Social Hygiene Society, vol. i, no. i.