VIII 
THE DEVELOPMENT OF HUMAN RACES 
183 
into some other animal as different from his present self as he 
is from the gorilla or the chimpanzee ; and who speculate on 
what this form is likely to be. But it is evident that such 
will not be the case ; for no change of conditions is con- 
ceivable which will render any important alteration of his 
form and organisation so universally useful and necessary to 
him, as to give those possessing it always the best chance of 
surviving, and thus lead to the development of a new species, 
genus, or higher group of man. On the other hand, we 
know that far greater changes of conditions and of his entire 
environment have been undergone by man than any other 
highly organised animal could survive unchanged, and have 
been met by mental, not corporeal adaptation. The difference 
of habits, of food, clothing, weapons, and enemies between 
savage and civilised man is enormous. Difference in bodily 
form and structure there is practically none, except a slightly 
increased size of brain, corresponding to his higher mental 
development. 
We have every reason to believe, then, that man may 
have existed, and may continue to exist, through a series of 
geological periods which shall see all other forms of animal 
life again and again changed ; while he himself remains un- 
changed, except in the two particulars already specified — the 
head and face, as immediately connected with the organ of 
the mind and as being the medium of expressing the most 
refined emotions of his nature, — and to a slight extent in 
colour, hair, and proportions, so far as they are correlated 
with constitutional resistance to disease. 
Summary 
Briefly to recapitulate the argument; — in two distinct 
ways has man escaped the influence of those laws which have 
produced unceasing change in the animal world. 1. By his 
superior intellect he is enabled to provide himself with cloth- 
ing and weapons, and by cultivating the soil to obtain a con- 
stant supply of congenial food. This renders it unnecessary 
for his body to be modified in accordance with changing con- 
ditions — to gain a warmer natural covering, to acquire more 
powerful teeth or claws, or to become adapted to obtain and 
digest new kinds of food, as circumstances may require. 2. 
