SELECTION ON MAN. 323 



affect the mental organization 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, although 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 modification, 

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

 organization ; 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 condi- 

 tions and the cumulative 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 further back in time, it is 

 natural to suppose that man's distribution over the 

 surface of the earth was less universal than at present. 

 Besides, Europe was in a great measure submerged 

 during the tertiary epoch ; and though its scattered 

 islands may have been uninhabited by man, it by no 

 means follows that he did not at the same time exist in 

 warm or tropical continents. If geologists can point 



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