58 NO STRUGGLE NO SELECTION 



part as the males in devouring the spawn and smaller 

 fish, whether of their own or of other kinds. 



But Nature has provided against the annihilation of 

 her finny tribes from this universal propension to 

 devour one another, by endowing them with an 

 enormous procreative power. The spawn of the cod 

 is said to contain about nine million eggs. Assume 

 that a cod produces in its lifetime fifty million eggs. 

 Of these only two will be hatched and come to 

 maturity and procreate their kind, the rest being 

 eliminated before they reach this last stage. The 

 enormous destruction of the cod in the various seas 

 where the fishing of it is prosecuted by the fishers of 

 all sea-going nations, does not from age to age seem 

 to affect their numbers. 



Notwithstanding the continuous drain upon them, 

 their numbers keep at the same point which they 

 would show if they were left undisturbed by the 

 toilers of the sea. The reason is that the continual 

 destruction of the adult devourers by the fishermen 

 permits a multitude of young cod to grow to maturity 

 which otherwise would have perished ; and thus the 

 annual destruction made by the fishing fleets, great as 

 it is, is balanced by the number of young cod saved alive. 



The potentiality of increase of prolific species 

 sometimes shows its actual power in a startling 

 manner, when the conditions of life of one of them 

 are by man's intervention altered, as has been the 

 case with the rabbit translated from this country 

 to Australia. 



