320 OPERATIONS SUBSIDIARY TO INDUCTION. 



rable burden upon the memory. When the names 

 of species become extremely numerous, some artifice 

 (as Mr. Whewell* observes) becomes absolutely 

 necessary to make it possible to recollect or apply 

 them. " The known species of plants, for example, 

 were ten thousand in the time of Linnseus, and are 

 now probably sixty thousand. It would be useless to 

 endeavour to frame and employ separate names for 

 each of these species. The division of the objects 

 into a subordinated system of classification enables us 

 to introduce a Nomenclature which does not require 

 this enormous number of names. Each of the genera 

 has its name, and the species are marked by the addi- 

 tion of some epithet to the name of the genus. In 

 this manner about seventeen hundred generic names, 

 with a moderate number of specific names, were found 

 by Linnaeus sufficient to designate with precision all 

 the species of vegetables known at his time." And 

 though the number of generic names has since greatly 

 increased, it has not increased in anything like the 

 proportion of the multiplication of known species. 



Philosophy of the Inductive Sciences, i., 489. 



