Elementary tipecies in Nature 35 



some simple changes. They were subordinated 

 to the parent-species. In other cases his spe- 

 cies were groups of lesser forms of equal value, 

 and it was not possible to discern which was 

 the primary and which were the derivatives. 



These two methods of subdivision seem in the 

 main, and notwithstanding their relatively im- 

 perfect application in many single examples, to 

 correspond with two really distinct cases. The 

 derivative varieties are distinguished from the 

 parent-species by some single, but striking mark, 

 and often this attribute manifests itself as the 

 loss of some apparent quality. The loss of 

 spines and of hairs and the loss of blue and red 

 flower-colors are the most notorious, but in 

 rarer cases many single peculiarities may dis- 

 appear, thereby constituting a variety. This 

 relation of varieties to the parent-species is 

 gradually increasing in importance in the esti- 

 mation of botanists, sharply contrasting with 

 those cases, in which such dependency is not to 

 be met with. 



If among the subdivisions of a species, no 

 single one can be pointed out as playing a pri- 

 mary part, and the others can not be traced 

 back to it, the relation between these lesser 

 units is of course of another character. They 

 are to be considered of equal importance. They 

 are distinguished from each other by more than 



