212 ENVIRONMENT 



with increasing rapidity, since each of these multi- 

 form changes in environment acts as an incentive 

 towards further change. But in tracing the 

 origin of this revolution we must avoid the danger 

 of mistaking a condition for a cause. The com- 

 plexity of modern life has afforded energetic and 

 industrious peoples opportunities for developing 

 the resources of their disposition. But the pos- 

 session of energy and industry is essential. During 

 the last half century the conditions of India have 

 been revolutionized by the construction of i ail- 

 ways and the diffusion of education. Yet the 

 general effect upon the outlook of the people has 

 been disappointingly small. However forcibly 

 advertised in the environment, the material ideals 

 of Europe do not impress Asia, where leisure is 

 preferred to industry, and men show their appre- 

 ciation of wealth by burying it in the ground. 



In human society the reproductive impulses 

 are very closely controlled by fashions, moral 

 rules and ambitions that conflict with them, and 

 it is exceedingly difficult to determine whether 

 variations in the birth-rate result from changes 

 in reproductive fertility or from various artificial 

 causes. Its very great fall amongst the peoples of 

 Western Europe, and of the Anglo-Saxon colonies, 

 may be due to the postponement of marriage 

 until long after the age that is indicated by 

 the arrival of puberty, or to the voluntary limi- 

 tation of families. But it is an accepted fact that 

 luxury in diet diminishes fertility. Indeed, under- 

 feeding appears to stimulate it : an Indian famine 

 is followed by a very extraordinary rise in the 

 birth-rate, amounting not infrequently to a third 

 above the normal. Families run large amongst 

 the thrifty Scotch, and the extraordinary fecun- 



