320 THE PRINCIPLES OF SEXUAL SELECTION. PAET H 
or young, would produce them of greater size or vigour; 
and the adults reared from such eggs or young would 
manifestly have the best chance of surviving, and 
would inherit a tendency towards lessened fertility- 
The parents, moreover, which had to nourish or provide 
for fewer offspring would themselves be exposed to » 
less severe strain in the struggle for existence, and 
would have a better chance of surviving. By tliesu 
steps, and by no others as far as I can see, natural 
selection under the above conditions of severe coni' 
petition for food, would lead to the formation of a lie" 
race less fertile, but better adapted for survival, than 
the parent-race. 
