540 GEOLOGY. 



mineral fertilizers, and the structural and ornamental materials of 

 stone and clay. These now control man's distribution and Lis aggre- 

 gate power, to a degree not even remotely approached a century ago, 

 and they are quite certain to be more influential in the future. 



Distribution and activity have also recently come to be affected 

 by the distribution of rejuvenated streams that arose from the defor- 

 mations of the late Tertiary periods, and by the stream-diversions of 

 the glacial period, both of which have furnished sources of water- 

 power heretofore neglected in the main. With little doubt, such 

 native sources of power are to play an increasingly large part in human 

 affairs as time goes on and the stored fuels are exhausted. 



With the increasing complexity of human activities, the localiza- 

 tion of the race will more and more depend on combinations of resources 

 and of conditions, and less upon single factors; but it is difficult to see 

 beyond the day when persistent fertility of the soil, under favorable 

 climatic conditions, coordinated with great supplies of ores, fuels, and 

 structural materials, will not constitute a decisive and controlling 

 advantage. 



Provincialism giving place to cosmopolitanism. — The early history 

 of human dispersal was marked by pronounced provincialism. The 

 early peoples were much isolated from one another by distance and 

 by natural barriers, and they themselves often interposed artificial 

 barriers against free inter-communication, and hence against the pres- 

 ervation of a common cosmopolitan type. So long as hunting and 

 fishing were the dominant pursuits, a wider and wider dispersion into 

 small tribes was a necessary tendency, which was abetted by conflict 

 of interests, strifes and wars, and the sentiments and customs that 

 arose from these. That such artificial sources of provincialism were 

 more effective than the natural ones seems to be implied by the fact 

 that while physiological differences sufficiently marked to readily 

 characterize varieties were numbered by hundreds, dialects sufficiently 

 different to prevent free intercourse were numbered by thousands. 

 Provincial sentiment to-day manifests itself more conspicuously in 

 language than in most other respects. The tendency to provincialism, 

 however, has never gone so far as to divide the race into distinct 

 species, forever separated by infertility. 



When efficient water-transportation was developed and the con- 

 trol of the sea was attained, a period of cosmopolitan tendency was 



