448 TEADITION AND HEEEDITY 



skill has been vastly accelerated, progress in the evolution of 

 mental characters has slowed down and may within the third 

 period have almost ceased. Selection within this last period has, 

 it may be remembered, come largely to be on account of disease. 

 The nature, therefore, of racial differences and the trend of 

 evolution of mental characters tend to confirm the conclusion 

 derived from a study of the influence of fertility and of contact — 

 namely, that the outstanding events are to be traced to environ- 

 mental rather than to germinal changes. But germinal changes 

 are not negligible. We have seen how these circumstances which 

 favoured progress in skill in the earlier part of the third period 

 also favoured mental evolution in just those directions in which 

 the white race is superior. Germinal changes may thus be 

 regarded as contributing to the progress which occurred at this 

 time ; evolution in the direction of self-assertion and other 

 qualities, which characterize the white races, must have accelerated 

 the cultural changes already in progress. When Mr. McDougall 

 says that ' in so far as differences of cultural level are associated 

 with differences of level of innate intellectual and moral quaHties, 

 cultural superiority must be regarded as the effect, rather than 

 the cause, of innate mental superiority V the above considerations 

 suggest another view. It would appear more probable that 

 cultural changes and germinal changes went hand in hand, and 

 that they were both products of the same environment ; no 

 doubt one kind of change reacted on the other, but there seems 

 as little reason for holding that the former were the effect of the 

 latter as for holding that the opposite was the case. Mr. McDou- 

 gall's view meets with considerable difficulties when we extend 

 our inquiry to the events within the third period. He attributes 

 the cultural level of the early civilizations to previous mental 

 evolution, but as he thinks that there has been no appreciable 

 evolution since that time, the events of the last five thousand 

 years including the continued progress in skill must be otherwise 

 accounted for. It is surely more probable that this series of 

 events beginning with the rise to the early civilizations and 

 continuing to the present day is in the main based upon one 

 determining cause. This we have found reason to identify with 

 the influence of fertility and contact upon the development of 

 tradition ; to germinal change we attribute in the earlier epochs 

 1 McDougall, Group Mind, p. 119. 



