AS APPLIED TO MAN. 335 



as thoroughly scientific and legitimate as that into the 

 origin of species itself. It is an attempt to solve the 

 inverse problem, to deduce the existence of a new 

 power of a definite character, in order to account for 

 facts which according to the theory of natural selection 

 ought not to happen. Such problems are well known 

 to science, and the search after their solution has often 

 led to the most brilliant results. In the case of man, 

 there are facts of the nature above alluded to, and in 

 calling attention to them, and in inferring a cause for 

 them, I believe that I am as strictly within the bounds 

 of scientific investigation as I have been in any other 

 portion of my work. 



The Brain of the Savage shoivn to be Larger than he 

 Needs it to be. 



Size of Brain an important Element of Mental 

 Power. The brain is universally admitted to be the 

 organ of the mind ; and it is almost as universally 

 admitted, that size of brain is one of the most impor- 

 tant of the elements which determine mental power 

 or capacity. There seems to be no doubt that brains 

 differ considerably in quality, as indicated by greater 

 or less complexity of the convolutions, quantity of grey 

 matter, and perhaps unknown peculiarities of organiza- 

 tion ; but this difference of quality seems merely to 

 increase or diminish the influence of quantity, not to 

 neutralize it. Thus, all the most eminent modern 

 writers see an intimate connection between the di- 

 minished size of the brain in the lower races of man- 



