188 NATURAL SELECTION ix 



useless at the time when they first appeared, became in the 

 highest degree useful at a much later period, and are now 

 essential to the full moral and intellectual development of 

 human nature, we should then infer the action of mind, 

 foreseeing the future and preparing for it, just as surely as 

 we do, when we see the breeder set himself to work with the 

 determination to produce a definite improvement in some culti- 

 vated plant or domestic animal. I would further remark that 

 this inquiry is 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 shown 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 important 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 gray 

 matter, and perhaps unknown peculiarities of organisation ; 

 but this difference of quality seems merely to increase or 

 diminish the influence of quantity, not to neutralise it. 

 Thus, all the most eminent modern writers see an intimate 

 connection between the diminished size of the brain in the 

 lower races of mankind, and their intellectual inferiority. 

 The collections of Dr. J. B. Davis and Dr. Morton give the 

 following as the average internal capacity of the cranium in 

 the chief races : Teutonic family, 94 cubic inches ; Esquimaux, 

 91 cubic inches; Negroes, 85 cubic inches; Australians and Tas- 

 manians, 82 cubic inches ; Bushmen, 77 cubic inches. These 



