184 HUMAN HISTOEY 



bability nearer 100,000 than 50,000 j'ears ago. In other words, 

 later Palaeolithic races must have had some thousands of years 

 of social organization behind them. Is then the peculiar rigidity 

 of the organization of primitive races altogether to be regarded 

 as an acquirement attained during the 15,000, 20,000, 30,000 

 years, or whatever the period may have been, since they have 

 been out of the main stream of progress ? It can scarcely be so. 

 A hardening of the system may have taken place, but not to such 

 an extent as to render it impossible to make comparisons between 

 primitive races and prehistoric races, and, what concerns us, to 

 render unacceptable the attribution to prehistoric races of those 

 general conditions of life found among primitive races, which 

 will form the subject-matter of the next two chapters. 



