152 WHAT IS DARWINISM? 



there are no two zoologists or any two bot- 

 anists who agree altogether in their classifi- 

 cation. Mr. Darwin says, " No clear line of 

 demarcation has yet been drawn between spe- 

 cies and sub-species, and varieties." (p. 61) 

 It is absolutely necessary, therefore, that a 

 distinction should be made between artificial 

 and natural species. No man asserts the im- 

 mutability of all those varieties of plants and 

 animals, which naturalists, for the convenience 

 of classification, may call distinct species. 

 Haeckel, for example, gives a fist of twelve 

 species of man. So any one may make fifty 

 species of dogs, or of horses. This is a mere 

 artificial distinction, which amounts to noth- 

 ing. There is far greater difference between a 

 pouter and a carrier pigeon, than between a 

 Caucasian and a Mongolian. To call the for- 

 mer varieties of the same species, and the 

 latter distinct species, is altogether arbitrary. 

 Nevertheless, notwithstanding the arbitrary 

 classifications of naturalists, it remains true 

 that there are what Professor Dana calls 

 " units " of the organic world. " When in- 

 dividuals multiply from generation to genera- 

 tion, it is but a repetition of the primordial 

 type-idea, and the true notion of the species is 



