The Theory of Natural Selection. 2 7 1 



phyletic modification (or inherited change of type) 

 indiscriminately, without waiting to consider whether 

 in particular cases its application is so much as 

 logically possible. The term ' ; natural selection " thus 

 becomes a magic word, or Sesame, at the utterance of 

 which every closed door is supposed to be immediately 

 opened. Be it observed, I am not here alluding to 

 that merely blind faith in natural selection, which of 

 late years has begun dogmatically to force this 

 principle as the sole cause of organic evolution in 

 every case where it is logically possible that the prin- 

 ciple can have come into play. Such a blind faith, 

 indeed, I hold to be highly inimical, not only to the 

 progress of biological science, but even to the true 

 interests of the natural selection theory itself. As to 

 this I shall have a good deal to say in the next 

 volume. Here, however, the point is, that the theory 

 in question is often invoked in cases where it is not 

 even logically possible that it can apply, and therefore 

 in cases where its application betokens, not merely an 

 error of judgment or extravagance of dogmatism, but a 

 fallacy of reasoning in the nature of a logical contra- 

 diction. Almost any number of examples might be 

 given ; but one will suffice to illustrate what is meant. 

 And I choose it from the writings of one of the 

 authors of the selection theory itself, in order to show 

 how easy it is to be cheated by this mere juggling 

 with a phrase for of course I do not doubt that a 

 moment's thought would have shown the writer the 

 untenability of his statement. 



In his most recent work Mr. Wallace advances an 

 interesting hypothesis to the effect that differences of 

 colour between allied species, which are apparently 



