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 Iam 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 tt 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- 
