316 THE ACTION OF NATURAL 
There is one point, however, in which nature will 
still act upon him as it does on animals, and, to some 
extent, modify his external characters. Mr. Darwin 
:has shown, that the colour of the skin is correlated 
with constitutional peculiarities both in vegetables and 
animals, so that liability to certain diseases or freedom 
from them is often accompanied by marked external 
characters. Now, there is every reason to believe 
that this has acted, and, to some extent, may still 
continue to act, on man. In localities where certain 
diseases are prevalent, those individuals of savage races 
which were subject to them would rapidly die off; 
while those who were constitutionally free from the 
disease would survive, and form the progenitors of a 
new race. These favoured individuals would probably 
be distinguished by peculiarities of colour, with which 
again peculiarities in the texture or the abundance 
of hair seem to be correlated, and thus may have 
been brought about those racial differences of colour, 
which seem to have no relation to mere temperature 
or other obvious peculiarities of climate. 
From the time, therefore, when the social and sym- 
pathetic feelings came into active operation, and the 
intellectual and moral faculties became fairly deve- 
loped, man would cease to be influenced by “ natural 
selection’ in his physical form and structure. As an 
animal he would remain almost stationary, the changes 
of the surrounding universe ceasing to produce in him 
that powerful modifying effect which they exercise 
over other parts of the organic world. But from the 
