DARWINISM ATTACKED. 75 



on insensibly changing physical conditions, but in a large 

 part on the presence of other species, on which it lives, or 

 by which it is destroyed, or with which it comes into com- 

 petition ; and as these species are already defined objects, 

 not blending one into another by insensible gradations, the 

 range of any one species, depending as it does on the range 

 of others, will tend to be sharply defined.' 



"Here we have a petitio principii. The sharp definition of 

 species, that we started out to account for, is explained by 

 the sharp definition of other species ! 



"A third part of the explanation is that, owing to the 

 relative fewness of individuals at the confines of the range 

 during the fluctuations of their enemies, or of their prey, 

 or in the nature of the seasons, they would be extremely 

 liable to utter extermination. If this were really the case, 

 then new species themselves which, on the theory, are at 

 first few in numbers ought to be exterminated. On the 

 whole, then, it does not appear that Darwin has been very 

 successful in his attempt to meet this objection to the 

 theory." 



A rather surprising objection is that of PfefTer, 8 who 



contends that selection cannot be the cause of the formation 



of species, for if it were real, however feeble 



Pfeffer's objec- . 



tion based on the lts effects, it would transform species much 

 slowness of spe- mO re rapidly than they are transformed; and in 



cies change, 



order to transform a species in a long time the 

 protection afforded by the selection of small additions or 

 modifications is so feeble as to be illusory. And adequate 

 protection under such a system of species transformation 

 is imperative. This is a curious argument, for it has always 

 been one of the claims of the mutationists that a "hurry- 

 up" theory is needed in order to satisfy the familiar objec- 

 tion that the physicists' estimate of the actual age of the 

 world is too low to admit of the production of the hosts of 

 kinds of animals and plants which we know to have existed 



