THE NAMING OF SPECIES 427 



are human conceptions,— the names of groups of 

 similar individuals, — enabling us to write and 

 speak of the forms of life. A species may be de- 

 fined as the unit in classification, designating an 

 assemblage of organisms which, in the judgment 

 of any person, is so marked and homogeneous 

 that it can be conveniently spoken of as one 

 thing. 



549. It does not matter, therefore, whether dif- 

 ferent botanists agree or not as to what are species 

 and what varieties of species, so long as one is 

 able to understand what the other means. By 

 giving names to the objects which we see, we are 

 able to classify and to put on record our knowl- 

 edge of them. . 



LXXXV. THE NAMING OF SPECIES 



550. It is necessary that we have names for 

 the kinds of plants. We must have a language. 

 Plants were first known by common-language 

 names, but obviously only common and conspicu- 

 ous plants can receive such names; and since 

 most people do not distinguish the kinds of plants 

 closely, it follows that common names cannot be 

 applied with precision. Most early authors de- 

 scribed plants in Latin phrases, referring similar 



