LINNXAN SYSTEM. oe 
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all those in each division possessing some feature in common, 
which distinguishes them from those in the other divisions ; 
so that, upon looking at a plant, we ean easily see to which 
division it belongs. The plants in each division are arranged 
in subdivisions or sections, each also possessing some well- 
marked character, which distinguishes the plants which it 
includes from those in the other subdivisions, and so on. 
The first or great divisions are called cuasses. The plants 
which each class contains are arranged in divisions called — 
orders. These again, are divided into sections, each of which 
is called a genus or family, chiefly characterised by the form 
of calyx, corolla, and seed-vessel; and lastly, the genus is 
subdivided into species, each distinguished by the form and 
other appearances of the root, stem, leaves, &c. Every 
plant has two names, the name of the genus (its generic 
name) and that of the species (its specific name) to which it 
belongs ; just as every man has two names—a sirname to 
tell his family, and a Christian name to distinguish him from 
the other members of the same family—the sirname being 
analogous to the generic name of a plant, and the Christian 
name to its specific name. In naming a plant, the generic 
name is placed first ; thus, Veronica hederifolia (Ivy-leaved 
speedwell.) Veronica (speedwell), is the generic name, and 
the specific name hederifolia (ivy-leaved), is added to dis- 
tinguish this plant from other kinds of Speedwell. 
640. The mode by which a beginner finds out the name 
of a plant is very simple indeed. He has a buok containing 
a description of all known plants. He is supposed to retain 
in his memory what is the distinguishing feature of each of 
the classes, and he examines the plant to ascertain which of — 
these features it presents. This being found out, he knows 
that the plant is one of those included in the correspond- __ 
ing class. There are twenty-four classes—he has fixed it _ 
_ in one of them, and has thus already made some progress. ag 
_ The plants which the class contains are arranged i in divisions 
(called orders), each of which, like the classes, possessessome = 
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