XXII 



. CONCLUSION 



1. AN attempt has been made to trace the origin of problems 

 of population from their source and to indicate their nature and 

 interdependence. They have been traced back to man's place 

 in nature. The ancestors of man must at one time have been 

 subject to the same conditions as those to which all species in 

 a state of nature are subject. These conditions were investigated, 

 and it was shown that fecundity is in the main determined by 

 the sum of all the dangers to which the young of any species 

 are exposed allowance being made for the fact that a certain 

 proportion of ova will not be fertilized. It was also shown that 

 change or history if history can be spoken of in this connexion 

 is due to germinal change alone, and it was further indicated 

 how it may be supposed that germinal change comes about. 

 The early stages in the moving away of the pre-human ancestor 

 from these conditions elude our inquiry, though certain deductions 

 may be made as to the main outline of what happened. For 

 evidence as to the latter stages, until we reach historical times, 

 we are chiefly dependent upon the method of using our knowledge 

 of existing primitive races as throwing light upon prehistoric 

 races. 



2. Problems of population fall under two main headings, 

 problems of quantity and problems of quality. But all problems 

 of population are interwoven one with another and the method 

 of solving any quantitative problem bears upon the quality of 

 population. Thus the methods of regulating quantity affect 

 quality by influencing germinal change, and in the later periods 

 of history growth in quantity affects quality by its influence 

 upon tradition. No one problem should be considered without 

 reference to its bearing both upon quantity and quality. At 

 the present day, for instance, differential fertility is almost 

 always considered solely from the point of view of quality ; it 

 is forgotten that the reduction in the birth-rate may be that 

 which economic conditions demand and that it may of necessity 



