ARE SPECIES STABLE? 43 



most evolutionists as incipient species. It has been 

 frequently urged as an argument against this view, 

 that when allowed to run wild these varieties return 

 to their original condition, all of these acquired 

 peculiarities disappearing. This is thought to show 

 that domestic varieties, and, therefore, presumably 

 all varieties, are simply oscillations from a central 

 form, to which return is made as soon as opportunity 

 admits. This is, of course, an argument for specific 

 stability. But, really, there is no ground for the 

 argument. It is simply an assumption that these 

 varieties return to their former ancestral condition. 

 In most cases, naturalists do not know what the 

 aboriginal stock was, and it is, therefore, impossible 

 rightly to make any such assumption as that on 

 which this claim is founded. It is true that our 

 domestic races do change very much when they 

 become wild. But this is not surprising. That our 

 carefully selected varieties should disappear under a 

 return to the feral condition, is a matter of course. 

 They have been produced under peculiar circum- 

 stances, and by very careful breeding. It would, of 

 course, follow, that as soon as these circumstances 

 are withdrawn the peculiar varieties would disap- 

 pear. So long as the conditions remain constant, 

 the varieties do not have any tendency to revert to 

 any former type, and this is all that the theory of 

 evolution requires. 



It is true enough that naturalists have been 

 unable to find a single unquestionable instance of 

 the production of a new species. It has been, 

 therefore, assumed by some who admit the theory 



