4 THE STUDY OF PLANTS 



7. Binomial nomenclature. To each of the different kinds of 

 plants and animals which "were l-:no\vn in his time, Linnceus gave a 

 name like the one above, consisting of two parts. In doing this he 

 made universal a principle very generally followed in the common 

 names with which we are most familiar. Thus we speak of the 

 White Mulberry, the Red [Mulberry, and the Black ^Mulberry. 

 Translated into Latin, these Ijecome the botanical names, ]\Ioruf! 

 alba, Morns rubra, ilorus nigra — the adjective part, as will be 

 noticed, following the noun Moms according to tlie rule commonly 

 observed in that language. So among the different kinds of oaks we 

 have Quercus alba, Quercus rubra, and Qucrcus nigra; and to certain 

 of the willows have been given the names Salix alba, Salix rubra, 

 and Salix nigra. It will lie seen that as the same component occurs 

 repeatedh' in the different names (just as in the names of persons 

 there are manj' Smiths, Bro^ois, and Robinsons and manj^ Johns, 

 Jameses, and Marys); so bj' adopting for plants the hinomial or 

 two-part system of naming, botanists are able to designate with 

 perfect accuracy the many thousand kinds of plants, by means of 

 a comparatively small number of words — a verj' much smaller 

 number in fact than would be required if each kind had to have a 

 name consisting of a .single word. Thus, in the examples given it 

 will be noticed that six words serve for naming nine different kinds 

 of plants. 



Another great advantage of the binomial method is that the 

 name alone may tell quite a good deal about the plant, for, as we 

 have seen, those sorts which resemble each other closely have the 

 first part of tlie name identical. From this the reader would know, 

 for example, that Qucrcus aquatica must be some kind of oak, and 

 Salix sericea, some sort of willow. 



8. Species. Ordinarily, there is no danger of being mis- 

 understood when we speak of such and such "sorts" or 

 "kinds" of plants, in the way that people commonh' do; 

 but when we come to a careful study of plants we find among 

 them such variety in the degrees of resemblance and differ- 

 ence that the necessitj' arises for a more precise means of 

 expressing ourselves. It thus l)ecomcs important to under- 

 stand something of the distinctions which naturalists recog- 

 nize between the different degrees of likeness among living 

 things. 



When from a dozen seeds out of the same pod, say of a 

 kidney-bean, we raise as many plants, there are twelve dis- 

 tinct individuals no two of which ar(> exactly alike in all 

 particulars. Yet despite their individual differences, they re- 



