[40] Spiller: Inter-Racial Problems, p. 35.
[41] Ratzel: History of Mankind, II, 380 ff.
[42] Industrial Evolution, p. 47.
[43] These and other references in this chapter are from Schneider: Culturfähigkeit des Negers.
[44] Atlanta University Leaflet, No. 19.
[45] Journal of the Royal Anthropological Institute, XLIII, 414, 415. Cf. also The Crisis, Vol. IX, p. 234.
[46] Bücher: Industrial Revolution (tr. by Wickett), pp. 57-58.
[47] Hayford: Native Institutions, pp. 95-96.
[48] Ratzel, II, 376.
[49] Hayford: Native Institutions, pp. 76 ff.