[136] Translated and adapted from Ludwig Gumplowicz, Der Rassenkampf, pp. 158-61. (Innsbruck: Wagnerische Univ. Buchhandlung, 1883.)
[137] Translated from Georg Simmel, Soziologie, by Albion W. Small, American Journal of Sociology, XV (1909), 296-98; III (1898), 667-83.
[138] Translated and adapted from Georg Simmel, Soziologie, pp. 646-51. (Leipzig: Duncker und Humblot, 1908.)
[139] Adapted from Charles Darwin, The Expression of the Emotions, pp. 350-67. (John Murray, 1873.)
[140] Adapted from Charles Darwin, The Expression of the Emotions, pp. 310-37. (John Murray, 1873.)
[141] Translated and adapted from L. Dugas, Psychologie du rire, pp. 32-153. (Félix Alcan, 1902.)
[142] Adapted from C. Lloyd Morgan, Animal Behaviour, pp. 193-205. (Edward Arnold, 1908.)
[143] Adapted from F. Max Müller, The Science of Language, I, 520-27. (Longmans, Green & Co., 1891.)
[144] Adapted from Charles H. Judd, Psychology, pp. 219-24. (Ginn & Co., 1917.)
[145] Adapted from Carl Bücher, Industrial Evolution. Translated by S. Morley Wickett, pp. 216-43. (Henry Holt & Co., 1907.)