60 DARWINISM AND THE PROBLEMS OF LIFE 



chapter, that each animal has the power to muhiply 

 so much that, if there were no hindrance, it would 

 gradually people the whole earth. Even a species 

 that has only six young ones in the course of life 

 would increase to 15,000,000 individuals in 500 

 years. 



We saw that each species bears young in proportion 

 to its peril, and that in each case the reproduction 

 is sufficient to maintain the species. We might now 

 ask whether the rate of reproduction is not increased 

 by natural selection. It is obvious that amongst the 

 hares of a particular district it is not only the swiftest 

 that have to care for progeny, but that those also 

 which bear more young than others will dominate in 

 the next generation. If one hare hcis ten young and 

 another twelve, is it not more probable that more of 

 the twelve will survive than of the ten, and that the 

 survivors of the larger brood will carry on the higher 

 fertility which they have inherited ? 



No. The inference is wrong. We know that species 

 have been put in a position to maintain themselves 

 by natural selection. In this there are two chief 

 methods open to selection. Either the multiplication 

 of the species is increased, cr its perils are diminished. 

 The effect is just the same in both cases. 



In the case of the hares, and in fact of all the 

 mammals, it is the second method that is chosen. 

 The animals are cunning and active so as to be able 

 to avoid many dangers. Above all, the new brood 

 is protected, especially by finding its shelter and food 

 inside the mother's body at first. It is otherwise with 



