ENVIRONMENT 141 



engender Die fall of dynasties and empires, the rise of 

 new , an<i the growth of new civilizations. If, 



on the contrary, a country becomes steadily less arid, and 

 the conditions of life improve, prosperity and commit- 

 ment ore the rule. Tln-n- U less temptation to war, and 

 im-iiV attmtion is I'-ft inon- fn-,- f,,r th- gentler arts 

 and sciences which make for higher civilization." 11 

 nionff priinitiv.- m-n th- natim- of tin- province 



which :i triU- happens to inhabit l-t.-rmine8 its mode 

 of lift-, in- Ill-tries, and hal.it-; ami th<->< in turn give 

 rise to various moral and menta . both good and 



bad. Thus definite .-h. acquired, and are 



passed on by inh.-ritance or training to future genera- 

 tions. It it be proved that the climate of any r 

 has changed during historic times, it follows that the 

 nature of the geographic provinces concerned must have 

 been altered more or less. For example, among th- 

 human inhabitants of Central Asia, widespread poverty, 

 want, and depression have been substitute! for compara- 

 tive competence, prosperity and contentment, hi- 

 orders, wars, migrations have arisen. Race has been 

 caused to mix with race under new physical conditions, 

 which have #i\ vn rise to new habits and character. The 

 impulse toward change and migration received in the 

 vast jjions of < Vntral \M:I has spread outward, 



and inY<>l\v.l all Kun>p<> in the confusion << Dark 



The pulsations of climate which have been important 

 rs in the movements of populations both in prehis- 

 and historic times are of several types. first 



type of climatic change is that of the Glacial period, dur- 

 ing which great fluctuations took place, probably simul- 

 of *<, r 



