[Heprinted from Thk Amkrican Natlkalist, Vol. XLII., Ai)iil, 1908.] 



THE TAXOXO:\[TC ASPECT OF THE SPECIES 



QUESTION 



DR. NATHANIEL LORD BRITTON 

 New York Botanical Garden 



1. Historic 



The ancients knew and described plants by generic 

 names. Their knowledge of them was general and super- 

 ficial. According to Adanson/ Conrad Oesner, 155!), 

 was the first to indicate the distinction of plants into 

 genera and species, although this advance is also claimed 

 for Columna. Subsequent authors in general, for about 

 a century, arranged s|:>ecies of plants under generic 

 names, but without definite rules for the limitations of 

 genera. Morison (1655), Ray (1682), and Tournefort 

 (1694), defined genera with reference to their fruits and 

 were followed by Linnaeus. 



Eay regarded specific differences as those that are 

 somewhat notable and fixed and not due to cultivation 

 and which cultivation does not change. The way to 

 determine these, according to him, is to grow them from 

 seed, because all the differences which are found in dif- 

 ferent plants grown from the same seed are accidental 

 and not specific, but he was not always exact in following 

 this rule. 



Tournefort declared that it troubled him very little 

 whether the plants he cited were species or varieties as 

 long as they differed in remarkable and perceptible 

 qualities; Adanson approves this view, remarking that 

 it seems to him sufficient and reasonable. 



From Linnjpus, Philosophia Botanica, 1751. 



We enumerate as many species as different forms 

 were originally created. 



^ Fam. des Plantes 1 : 102. 1763. 



225 



