18 Principles of Plant Culture. 



the study of breeding, we need to know something of 

 the principles of classification. 



21. Classification is the arrangement of the different 

 kinds of plants and animals into groups and families 

 based on individual resemblances. If we examine plants 

 as they are growing in nature, we may observe (a) that 

 there are many plants of the same kind, and (&) that 

 there are many kinds of plants. The different plants 

 or animals of the same kind are called individuals, and, 

 in general, we may say that the different kinds of 

 plants or animals are called species (spe'-cies). But 

 these simple distinctions are not sufficient to satisfy the 

 needs of natural history. We might say, for example, 

 that the violet is one kind of plant and the oak is an- 

 other, which is true; but there are also different kinds 

 of violets and different kinds of oaks. We might say 

 that the apple is one kind of plant and the pear is an- 

 other, but there are different kinds of apples, as the 

 crab apple and the common apple, and there are differ- 

 ent kinds of crab apples, and of common apples. We 

 must not only arrange the kinds of plants into groups, 

 but- we must have groups of different grades. For ex- 

 ample, botanists call each distinct kind of plant, as 

 the sugar maple, the white oak and the dandelion, a 

 species. Then the species that rather closely resemble 

 each other are formed into groups, each of which is 

 called a genus (ge'-nus), plural, genera (gen'-e-ra) as 

 the sugar maple and the soft maple ; the white oak, the 

 red oak and the bur oak; the raspberry and the black- 

 berry; and the apple, pear and quince. Then the gen- 

 era that resemble each other, as the one containing the 



