species, Subspecies and Varieties. 171 



lows that varieties are nothing less than a particular 

 form of species. Varieties are only small species, as 

 Darwin has said.^ 



Jordan's elementary species are distinguished from 

 one another not by one peculiarity but in nearly all their 

 characters. This is an extremely important point. There 

 is absolutely no justification for regarding them as vari- 

 eties. If we wish to treat them as subdivisions of the 

 old species they must be called subspecies. I prefer to 

 call them elementary species. Darwin speaks repeatedly 

 of specific elements when he is referring to their indi- 

 vidual characters.^ 



There is little prospect that an agreement between 

 all the workers in this field will ever be brought about. 

 Theoretically in my opinion we should be perfectly justi- 

 fied in applying the coveted distinction of ''species" to 

 these elementary forms, whose limits are not set by our 

 imagination. But practically it is for many reasons more 

 convenient to refer to the artificial groups of these, that 

 is, the collective species, simply as species. Where we 

 are concerned with the investigation of the origin of a 

 single species we mean of course an elementary one. 

 The other species are groups whose origin is a matter 

 of history and cannot for this reason be dealt with ex- 

 perimentally. 



Thus we see that Linnean species are collective and 



artificial whilst Jordan^'s species are single and real. 



Each collective species consists of a larger or smaller 



group of subspecies or elementary species; in the deter- 



'^ Life and Letters, II. p. T05. Darwin's more famous aphorism 

 that varieties are incipient species is less happy. We know nothing 

 about the age of most varieties. 



^ E. g., Variations in Animals and Plants, IT. p. 23. Each of 

 these elements is represented in the germ, according to the theory 

 of Pangenesis, by a unit, the Pangene. 



