SYSTEMATIC BOTANY. 77. 
633. A great many different systems for the classification 
of plants have been proposed, some natural, some artificial, 
some of a mixed nature. At present, the systems followed 
are the artificial r sexual system of Lixnzus, and the na- 
tural method followed by Jussrev, improved and extended 
by subsequent botanists. 
634, The system of Linneus was founded on the number 
of the stamens. This was made to determine the primary 
divisions or classes: the subdivisions or orders, in most 
cases, depend on the number of pistils. These two sys- 
tems (of Tournefort and Linneus) are artificial methods. 
When we are informed that a plant belongs to a particular 
class in the Linnzean System, we know only the number of 
the stamens—_we neither know any of its other characters, 
nor can we have any idea of its properties. 
635. According to the method of Jussieu, plants are 
grouped together, not because they may agree in the strue- 
ture or number of any single organ, but because, on taking 
all their different characters into consideration, they are 
found to bear a strong resemblance to each other ; and we 
also find that, in general, the properties of plants are similar 
jm those which are like in their external characters. For 
these reasons, it is generally called the Natural System. An 
_ dequaintance with it affords a broad, comprehensive, and 
Scientific view of the vegetable creation; and it embodies 
much important information regarding the structure, phy- 
siology, and properties of plants, and their mutual relations. 
Though this is the system which it must always be the ob- 
Ject of botanical science to perfect, and with which it is ne- 
cessary for every student of botany to be intimately ac- 
quainted ; as it has not been found possible to simplify it as 
tem must also be acquired. From its comparative simpli- 
tity, it is very convenient for those commencing the study ; 
and indeed, till within these few years, it alone was followed” 
in this country. Accordingly, these two methods will be 
explained in the present work. ees 
much as could be desired, a knowledge of the Linnzan Sys- _ 
