COMPARING AND CLASSIFYING PLANTS. 61 



elusions of the book, unless, on comparing them with 

 your own plants, you see that they are true. 



There are two botanical expressions, of which, at 

 the outset, you should learn the meaning. One of 

 these is the characters of plants, and the other the 

 affinities of plants. And, first, what is meant by 

 plant-characters f 



If you will describe a buttercup, I think we can 

 easily find just what is meant. 



You say, " CALYX, sepals, 5, polysepalous, inferior ; 

 COROLLA, petals, 5, polypetalous, hypogynous; STA- 

 MENS, many, hypogynous ; PISTIL, carpels, many, apo- 

 carpous, superior." Yes; but what about the rest 

 of the plant? You answer: "It has simple, exstipu- 

 late, alternate, divided leaves; petiole spreading at 

 base ; stem, erect ; flowers, in a loose cluster ; juice, 

 watery, acrid. 



Now, this is the description of a particular but- 

 tercup, and yet it applies to all buttercups. Are all 

 buttercups, therefore, exactly alike? By no means. 

 They differ in size, shape, thriftiness, number of 

 blossoms, etc. ; but, in our botanical description, we 

 do not record these individual peculiarities. 



"Well, the points of form and structure in which 

 all buttercups agree, that is, their permanent feat- 

 ures, are called by botanists the characters of the 

 buttercup. All such unchanging features of plants 

 are plant-characters. A plant is simply an assem- 

 blage of characters, and the description of a plant is 

 but a list of its characters. 



Now, it is by comparing groups of characters that 

 we reach the idea of affinities. If, as we have seen, 

 each plant bears a fixed group of characters, the re- 



