86 A NEW THEORY OF EVOLUTION. 



lated by the effects of the struggle and by 

 heredity, and thus ultimately a new species 

 is evolved. 



But although the animals that survive 

 have evidently proved themselves fitter than 

 those that succumbed, that does not prove 

 that they are fitter than if there had been no 

 struggle, or that they themselves are as fit 

 as when the struggle began. 



Let us suppose a colony of fifty rabbits 

 on an island capable of sustaining not more 

 than a hundred without a struggle for food. 

 While grass is abundant, arid the conditions 

 of life are in every respect favourable, the 

 rabbits multiply, and in a few generations 

 the highest expression of their type will 

 probably be developed. But when the colony 

 exceeds a hundred, the struggle for existence 

 will begin and go on continuously. 



What will be the result of the struggle 

 after six months have passed ? The rabbits 

 that possessed the greatest vitality, and 

 were able to live on the smallest quantity 

 of food, will have proved themselves fitter 

 than those less highly endowed, and will 

 survive ; whilst the feeblest, when the 

 struggle began, will have been starved out 

 of existence. But have the surviving rab- 

 bits come out of the struggle unscathed ? 



