NATURAL SELECTION 



an advance in mind rather than by a change in body. If, 

 therefore, we are of opinion that he was not really man till 

 these higher faculties were fully developed, we may fairly 

 assert that there were many originally distinct races of men ; 

 while, if we think that a being closely resembling us in form 

 and structure, but with mental faculties scarcely raised above 

 the brute, must still be considered to have been human, we 

 are fully entitled to maintain the common origin of all man- 

 kind. 



The Bearing of these Views on the Antiquity of Man 

 These considerations, it will be seen, enable us to place the 

 origin of man at a much more remote geological epoch than 

 has yet been thought possible. He may even have lived in 

 the Miocene or Eocene period, when not a single other 

 mammal was identical in form with any existing species. 

 For, in the long series of ages during which these primeval 

 animals were being slowly changed into the species which now 

 inhabit the earth, the power which acted to modify them 

 would only affect the mental organisation of man. His brain 

 alone would have increased in size and complexity, and his 

 cranium have undergone corresponding changes of form, while 

 the whole structure of lower animals was being changed. 

 This will enable us to understand how the fossil crania of 

 Denise and Engis agree so closely with existing forms, al- 

 though they undoubtedly existed in company with large 

 mammalia now extinct. The Neanderthal skull may be a 

 specimen of one of the lowest races then existing, just as the 

 Australians are the lowest of our modern epoch. We have 

 no reason to suppose that mind and brain and skull modifica- 

 tion could go on quicker than that of the other parts of the 

 organisation ; and we must therefore look back very far in 

 the past to find man in that early condition in which his 

 mind was not sufficiently developed, to remove his body from 

 the modifying influence of external conditions and the cumu- 

 lative action of natural selection. I believe, therefore, that 

 there is no a priori reason against our finding the remains of 

 man or his works in the tertiary deposits. The absence of 

 all such remains in the European beds of this age has little 

 weight, because, as we go farther back in time, it is natural 



