EVOLUTION AND ITS CONSEQUENCES. 5 



position of strong opposition. But the earnest objector says, you 

 have not after all shown me any real transitions from species to 

 species ; until that is done your development is but a supposition. 



The all-sufficient answer to this statement is to be found in 

 the imperfection of our system of classification. Thus, if we first 

 assume, with the anti-developmentalist, that varieties have a com- 

 mon parentage, and species distinct ones, when intermediate forms 

 connecting so-called species are discovered, we must confess our- 

 selves in error, and admit that the forms supposed to have had 

 a different origin really had a common one. Such intermediate 

 forms really establish the connection between species, but the 

 question is begged at once by asserting unity of species, and, 

 therefore, of origin, so soon as the intermediate form is found ; 

 for, as before observed, it is not degree, but constancy of distinc- 

 tion, which establishes the species of the zoological systems. 

 Transitions between species are constantly discovered in existing 

 animals ; when numerous in individuals, the more diverse forms 

 are regarded as *^ aberrant"; when few, the extremes become 

 *^ varieties," and it is only necessary to destroy the annectant 

 forms altogether to leave two or more species. As the whole of a 

 variable species generally has wide geographical range, the vari- 

 eties coinciding with sub-areas, the submergence, or other change 

 in the intervening surface, would destroy connecting forms, and 

 naturally produce the isolated species. 



Formerly naturalists sometimes did this in their studies. A 

 zoologist known to fame once pointed out to me some trouble- 

 some specimens which set his attempts at definition of certain 

 species at defiance. *' These," said he, ''are the kind that I 

 throw out of the window." Naturalists having abandoned throw- 

 ing puzzling forms out of the window, the result of more honest 

 study is a belief in evolution by nine tenths of them. 



But, says the inquirer again, your variations and transitions 

 are but a drop in the ocean of well-disting-uished species, classes, 

 etc. The permanent distinction of species is matter of every-day 

 observation ; your examples of changes are few and far between, 

 and utterly insufficient for your purpose. 



It is true that the cases of transition, intermediate forms, or 

 diversity in the brood, observed and cited by naturalists in proof of 

 evolution, are few compared with the number of well-defined, iso- 

 lated species, genera, etc., known ; though far more numerous 

 than the book-student of natural history is apt to discover. But 



