114 ADAPTATION AND PROGRESS 



coast : this is the dominant fact of American history. China forms a section 

 of the Pacific rim. This is the fact back of the geographic distribution of 

 Chinese emigration to Annam, Tonkin, Siam, Malacca, the Philippines, East 

 Indies . . . Ecuador and Peru. 



As the earth is one, so is humanity. Its unity of species points to some 

 degree of communication through a long prehistoric past. Universal history 

 is not entitled to the name unless it embraces all parts of the earth and all 

 peoples, whether savage or civilized. To fill the gaps in the written record it 

 must turn to ethnography and geography, which by tracing the distribution 

 and movements of primitive peoples can often reconstruct the most impor- 

 tant features of their history. 1 



There are four fundamental classes of geographic influences 

 according to our author: (i) direct and indirect physical, (2) 

 direct and indirect psychical, (3) economic and social, and (4) 

 effects upon movements of peoples. As illustrations of the direct 

 effects working in conjunction with natural selection and espe- 

 cially potent on primitive man, we have variations in stature, 

 pigmentation and acclimatization; and of the indirect effects, 

 such anatomical changes as result from certain occupations, 

 these in turn being due to physical environment as in the case of 

 the thin legs and thick arms of the Payaguas Indians due to so 

 much of their life being spent in canoes. 2 The psychical effects 

 are registered in differences in temperament which differentiate 

 peoples as well as in differences in literature and religion, while 

 the indirect effects are seen in peculiarities of language reflecting 

 local conditions and occupations. 3 Under the third class we have 

 the effect of physical environment on a group through the natural 

 resources provided, the occupations encouraged or discouraged 

 and the facilities for exchange offered; and under the fourth 

 class, " the effect of natural barriers ... in obstructing or de- 

 flecting the course of migrating people and in giving direction to 

 national expansion, . . . the tendency of river valleys and tree- 

 less plains to facilitate such movements, the power of rivers, lakes, 

 bays and oceans either to block the path or open a highway, . . . 

 and finally the influence of all these natural features in detemm'n- 



1 Influence of Geographic Environment, p. 30. 



2 Ibid., pp. 34 f. If due merely to occupation these characters would not be in- 

 herited. 



3 Ibid., p. 41. 



