Darwin, Descent of Man, p. 33. New York, 1899.

D. Livingstone, Missionary Travels, p. 266. New York, 1858.

Alaska, Eleventh Census Report, pp. 54, 56. Washington, 1893, and Albert P. Niblack, The Coast Indians of Southern Alaska and Northern British Columbia, p. 237. Washington, 1888.

Fitz-Roy, Voyage of the Beagle, Vol. II, pp. 130-132, 137, 138. London, 1839.

H. Bancroft, Native Races, Vol. I, pp. 88-89. San Francisco, 1886.

S. Stanhope Smith, Essay on the Causes of the Variety of Complexion and Figure in the Human Species, pp. 103-110. New Brunswick and New York, 1810.

For full discussion see A.R. Wallace's article on acclimatization in Encyclopedia Britanica, and W.Z. Ripley, Races of Europe. Chap. XXI. New York, 1899.

D.G. Brinton, Races and Peoples, pp. 39-41. Philadelphia, 1901.

Darwin, Descent of Man, pp. 34-35. New York, 1899.

E.F. Knight, Where Three Empires Meet, pp. 137-138. London, 1897.