[107] Roscher, _Grundlagen des National-Oekonomik_, Book VI. _Bevoelkerung_, p. 694, Note 5. Stuttgart, 1886. [108] Edward John Payne, History of the New World Called America, Vol. I, p. 303-313. Oxford and New York, 1892. [109] Roscher, _National-Oekonomik des Ackerbaues_, pp. 31, 52. Stuttgart, 1888. [110] _Ibid._, p. 56, Note 5. [111] For these and other averages, Sir John Lubbock, Prehistoric Times, pp. 593-595. New York, 1872. [112] Roscher, _National-Oekonomik des Ackerbaues_, pp. 79-80, p. 81, Note 7. Stuttgart, 1888. William I. Thomas, Source Book for Social Origins, pp. 96-112. Chicago, 1909. [113] Capt. J. Forsyth, The Highlands of Central India, pp. 101-107, 168. London, 1889. [114] Tacitus, _Germania_, III. [115] Roscher, _National-Oekonomik des Ackerbaues_, p. 32, Note 15 on p. 36. Stuttgart, 1888. [116] E. Huntington, The Pulse of Asia, pp. 202, 203, 212, 213, 236-237. Boston, 1907. [117] Sheldon Jackson, Introduction of Domesticated Reindeer into Alaska, pp. 20, 25-29, 127-129. Washington, 1894. [118] Quoted in Alexander von Humboldt, Aspects of Nature in Different Lands, pp. 62, 139. Philadelphia, 1849. [119] Edward John Payne, History of the New World Called America, Vol. I, pp. 311-321. 333-354, 364-366. New York, 1892. [120] Prescott, Conquest of Peru, Vol. I, p. 47. New York, 1848. [121] McGee and Thomas, Prehistoric North America, Vol. XIX, pp. 151-161, of _The History of North America_, edited by Francis W. Thorpe, Philadelphia, 1905. [122] Ratzel, _Anthropo-geographie_, Vol. II, pp. 264-265. [123] Malthus, Principles of Population, Chapters V and VII. London, 1878. [124] Nathaniel Shaler, Nature and Man in America, pp. 147-151. W.Z. Ripley, Races of Europe, Chap. I, New York, 1899. [125] Justus Perthes, _Taschen-Atlas_, pp. 44, 47. Gotha, 1910. CHAPTER IV THE MOVEMENTS OF PEOPLES IN THEIR GEOGRAPHICAL SIGNIFICANCE [Sidenote: Universality of these movements.]