4 THE STUDY OF PLANTS 



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

 plants and animals which were known in his time, Linna-us gave.a 

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

 made universal a principle very generall}^ followed in the common 

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

 White iNIulberry, the Red Mulberry, and the Black Mulberry. 

 Translated into Latin, these become the botanical names. Morns 

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

 noticed, following the noun Morns according to the rule commonly 

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

 have Quercns alba, Qnercns rnbra, and Quercns nigra; and to certain 

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

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

 repeatedly in the different names (just as in the names of persons 

 there are many Smiths, Browns, and Robinsons and many Johns, 

 Jameses, and Marys); so I\y adopting for plants the binomial or 

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

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

 a comparativelj^ small number of words — a very much smaller 

 numlicr in fact than would be recjuired if each kind had to have a 

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

 will be noticed that si.\ 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 the name identical. From this the reader would know, 

 for example, that Qnercns aqnatica 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 commonly 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 necessity arises for a more precise means of 

 expressing ourselves. It thus becomes important to under- 

 stand something of the distinctions which naturalists recog- 

 nize between the difTerent degrees of likeness among living 

 things. 



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

 kidney-bean, we raise as man3' plants, there are twelve dis- 

 tinct individuals no two of which are exactly alike in all 

 particulars. Yet despite their individual differences, they re- 



