Criticisms of Theory of Natural Selection. 375 



lieve it to have been the chief factor or principal cause, 

 all the three objections in question necessarily vanish. 

 For in this case, even if it be satisfactorily proved that 

 the theory of natural selection is unable to explain the 

 three classes of facts above mentioned, the theory is 

 not thereby affected : facts of each and all of these 

 classes may be consistently left by the theory to be 

 explained by causes other than natural selection 

 whether these be so far capable or incapable of 

 hypothetical formulation. Thus it is evident that 

 whether the three objections above named are to 

 be regarded as logically insurmountable by the 

 theory, or as logically non-existent in respect to it, 

 depends simply upon the manner in which the theory 

 itself is stated. 



In the next volume a great deal more will have to 

 be said upon these matters especially with regard to 

 the causes other than natural selection which in my 

 opinion are capable of explaining these so-called 

 " difficulties." In the present connexion, however, 

 all I have attempted to show is, that, whatever may 

 be thought touching the supplementary theories 

 whereby I shall endeavour to explain the facts of 

 inutility, cross-sterility, and non-occurrence of free 

 intercrossing, no one of these facts is entitled to rank 

 as an objection against the theory of natural selection, 

 unless we understand this theory to claim an ex- 

 clusive prerogative in the field of organic evolution. 

 This, as we have previously seen, is what Mr. Wallace 

 does claim for it ; while on the other hand, Mr. 

 Darwin expressly and even vehemently repudiates 

 the claim : from which it follows that all the three 

 main objections against the theory of natural selection 



