276 Darwin, and after Darwin. 



a posteriori, taking the arguments which have been 

 advanced in favour of the doctrine, other than those 

 which rest upon the fallacious definition. These 

 arguments, as presented by Mr. Wallace, are two in 

 number. 



First, it is represented that natural selection must 

 occupy the whole field, because no other principle 

 of change can be allowed to operate in the presence 

 of natural selection. Now I fully agree that this 

 statement holds as regards any principle of change 

 which is deleterious, but I cannot agree that it does 

 so as regards any such principle which is merely 

 neutral. No reason has ever been shown why natural 

 selection should interfere with * ! indifferent " characters 

 to adopt Professor Huxley's term supposing such 

 to have been produced by any of the agencies which 

 we shall presently have to name. Therefore this 

 argument or rather assertion goes for nothing. 



Mr. Wallace's second argument is, that utility is 

 the only principle which can endow specific characters 

 with their characteristic stability. But this again 

 is mere assertion. Moreover, it is assertion opposed 

 alike to common sense and to observable fact. It 

 is opposed to common sense, because it is obvious 

 that any other principle would equally confer stability 

 on characters due to it, provided that its action is 

 constant, as Darwin expressly held. Again, this 

 argument is opposed to fact, because we know of 

 thousands of cases where peculiar characters are 

 stable, which, nevertheless, cannot possibly be due 

 to natural selection. Of such are the Porto Santo 

 rabbits, the niata cattle, the ducks in St. James' 

 Park, turkeys, dogs, horses, &c., and, in the case of 



