[1059] Ratzel, History of Mankind, Vol. II, p. 220. London, 1896-1898.

[1060] Genesis, XIII, 2, 5.

[1061] James Bryce, Impressions of South Africa, p. 474. New York, 1897.

[1062] Eleventh Census, Indian Report, pp. 143-144. Washington, 1894.

[1063] Sven Hedin, Central Asia and Tibet, Vol. I, pp. 18-20. London and New York, 1903.

[1064] J.L. Burckhardt, Notes on the Bedouins and Wahabys, Vol. I, pp.

32-33. London, 1831.

[1065] George Adam Smith, Historical Geography of the Holy Land, pp.

8-10. New York, 1897.

[1066] Gibbon, Decline and Fall of the Roman Empire, Vol. V, pp. 78-79.

New York, 1858.

[1067] L. March Phillipps, In the Desert, p. 95. London, 1905.

[1068] Sir Samuel W. Baker, The Nile Tributaries of Abyssinia, pp. 88, 128, 129, 135. Hartford, 1868.

[1069] Journey of John de Carpini and William de Rubruquis in 1253, pp.

8, 217. Hakluyt Society, London, 1903.

[1070] James Bryce, Impressions of South Africa, pp. 107, 421. New York, 1897.

[1071] Wilhelm Roscher, _National-Oekonomik des Ackerbaues_, p. 44.

Stuttgart, 1888.

[1072] A full discussion in Malthus, Principles of Population, Book I, chap. 7.

[1073] J.L. Burckhardt, Notes on the Bedouins and Wahabys, Vol. I, pp.

133-144, 157-160. London, 1831. S.M. Zwemer, Arabia, The Cradle of Islam, 155-157. New York, 1900.

[1074] Vambery, _Reise in Mittelasien_, pp. 285, 289-297. Leipzig, 1873.

[1075] Alexis Krausse, Russia in Asia, pp. 127-129. New York, 1899.

[1076] Ratzel, History of Mankind, Vol. III, pp. 174-175. London, 1896-1898.

[1077] Wallace, Russia, pp. 340-342. New York, 1904.

[1078] L. March Phillipps, In the Desert, pp. 17, 63-66. London, 1905.

[1079] Felix Dubois, Timbuctoo, pp. 256, 324-325. Translated from the French, New York, 1896.

[1080] Heinrich Barth, Travels in North and Central Africa, Vol. I, pp.

287-288, 293, 305. New York, 1857.

[1081] Felix Dubois, Timbuctoo, pp. 133-134, 203, 206-207, 229, 232, 239-245. New York, 1896.

[1082] Boyd Alexander, From the Niger to the Nile, Vol. II, pp. 1-2, 6, 16-18, 80. London, 1907.

[1083] Gibbon, Decline and Fall of the Roman. Empire, Vol. V, p. 87. New York, 1858.

[1084] Pliny, _Historia Naturalis_, V, 3.

[1085] Gibbon, Decline and Fall of the Roman Empire, Vol. II, p. 495.

New York, 1858.

[1086] Ellsworth Huntington, The Pulse of Asia, p. 340. Boston, 1907.

[1087] Pallas, Travels in the Southern Provinces of Russia in 1793-1794, Vol. II, p. 4. London, 1812.

[1088] _Ibid._, Vol. I, pp. 94, 256.

[1089] Genesis, XIII, 7-8; XXI, 25-30; XXVI, 15-22.

[1090] Herbert Spencer, Principles of Sociology, Vol. I, p. 545. New York, 1887.

[1091] Thucydides, Book II, 96.

[1092] Herodotus, IV, 46.

[1093] Meredith Townsend, Asia and Europe, Chapter on Arab Courage. New York, 1904.

[1094] Wilhelm Roscher, _National-Oekonomik des Ackerbaues_, p. 44.

Stuttgart, 1888.

[1095] J.L. Burckhardt, Notes on the Bedouins and Wahabys, Vol. I, pp.

35-36. London, 1831.

[1096] John de Plano Carpini, Journey to the Northeast, pp. 114-117, 120-125. Hakluyt Society, London, 1904.

[1097] Ratzel, History of Mankind, Vol. I, p. 28. London, 1896-1898.

[1098] J.H. Speke, Discovery of the Source of the Nile, pp. 241-244. New York, 1868.

[1099] Journey of William de Rubruquis, pp. 18-27, Hakluyt Society, London, 1900.

[1100] Jerome Dowd, The Negro Races, Vol. I, pp. 225-232. New York, 1907.

[1101] Sir Francis Younghusband, The Heart of a Continent, pp. 85-98.

London, 1904.

[1102] Ratzel, History of Mankind, Vol. I, p. 170. London, 1896-1898.