Principles of Classification-* 13 
ought to be adopted in the discrimination of the spe» 
cies which have been already enumerated among the- 
generic marks. For the sake of brevity Linnaeus limit- 
ed his specific definitions to twelve words, a rule which 
has been followed by succeeding naturalists, especially 
those who have employed the Latin language jin which 
it is most practicable. 
In the construction of generic and specific charac- 
ters, the arrangement of the different parts from which 
these marks are derived ought to be attended to. The 
most important in the natural order, or genus, are first 
mentioned, and the subordinate, or more particular 
marks of the object to which they are applied, ought to 
conclude the description ; but in drawing up the natu- 
ral characters of a genus, the calyx, corolla, stamens, 
pistils, seed-vessel, seed, and receptacle, are to be des- 
cribed in their order ; and the root, stem, leaves, appen- 
dages, flower, and fruit, point out the arrangement, 
when a full description, of any particular plant is re- 
quired*. 
Sections .-, — The labour of research is greatly abridged 
and facilitated by associating together such genera and 
species as are allied by certain marks. Such groups of 
genera and species are distributed into sections ; and, 
each section being particularly characterised, if it shall 
appear that the plant possesses the character of that 
section, after the class and order have been ascertained, 
and the genus to which it belongs is sought for, it is 
only necessary to compare it with the descriptions com- 
prehended under that particular section. Thus the po- 
sition of the germen furnishes marks for the formation 
of two sections in certain genera, which are characteris- 
ed by having the flower superior or inferior, as when 
B 2 
