578 
THE PRINCIPLES OF BOTANY. 
With every altered condition and circumstance new plants 
start up. The mountain-side has its own races of vegetable 
inhabitants, and the valleys have theirs; the tribes of the 
sand, the granite, and the limestone are all different; and the 
sun does not shine upon two degrees on the surface of this 
globe the vegetation of which is identical; for every latitude 
has a Flora of its own. In short, the forms of seas, lakes, 
rivers, islands, and peninsula, hills, valleys, plains, and 
mountains, are not so infinitely diversified as that of the 
vegetation which adorns them.” 
In dealing, then, with a subject so vast, it is our intention 
merely to glance at some of the work that has been done 
before, and then to adopt some easy system of classes, with 
the view of, under such heads, directing attention to some of 
the more important individuals. 
For a long time two systems of classification have been em¬ 
ployed by botanists, the one termed the artificial system 
having been invented by Linnseus, and hence called the 
Linneean system; the other founded by Jussieu, called the 
natural system. 
The first of these is in the main founded on the stamens 
and pistils, either in respect to their numbers or their arrange¬ 
ment ; but the first page of such an arrangement of the 
English flora will at once show that the system is artificial; 
thus under the class Diandria, two stamens—order Mono- 
gynicij we have the shrubby privet, the herbaceous speed¬ 
wells, the tall ash-tree, the minute floating duckweed of the 
pond, and our common grasses—an allocation which the 
most ignorant will recognise as wholly unnatural; indeed, it 
is quite as artificial as is the array of words in a dictionary, 
which are brought together in the same column merely on 
account of a similarity in the first three or four letters, and 
how perfectly unnatural this is we need not stop to prove, 
though we must admit, at the same time, that it is highly 
convenient, and so, indeed, was the Linnaean system; but 
since we have a system which is convenient for study, and, 
besides, brings plants together having a natural affinity, we 
are enabled to base our classification upon the grammar of 
the science, and we now, therefore, give a list of the classes, 
with their more prominent distinctive characters. 
The classes of plants may be founded either upon some 
important point in the arrangement of its bulk, or, which is 
better, though the one is convertible into the other, on the 
organs of reproduction, either in the shape of the petals or 
the seeds, or of both ; thus Jussieu, in 1774, founded three 
great groups— Acolyledons, Monocotyledonsy Dicotyledons, 
