18 Principles of Plant Culture. 



there are many plants of the same kind, and (6) that there 

 are many kinds of plants. The different plants or ani- 

 mals of the same kind are called in<2t#tdtui&,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 another, 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 another, but there are different kinds of 

 apples, as the crab apple and the common apple, and 

 there are different 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 example, 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 genera 

 that resemble each other, as the one containing the apple, 

 pear and quince, and the one containing the plum, cherry 

 and peach, are formed into other groups called families.* 

 Thus families are made up of genera, and genera are made 

 up of species. There may be, also, different varieties in 

 the same species, as the different varieties of apple, pea,, 

 or strawberry. 



* Related families are often further united into orders. 



