CLASSES.—SUB-KINGDOMS. 405 
Thus we have the classes Monocotyledones and Dicotyledones, 
which possess certain distinctive characters in their respective 
embryos, &c. 
The Classes are also divided into Suwh-classes, Series, Cohorts 
or Alliances, and other divisions, in the same manner as the 
orders, genera, and species are subdivided ; but as the names of 
such divisions vary in different systems, and are all more or less 
artificial, it is not necessary for us, in this place, to dwell upon 
them further. The classes themselves, in different systems, are 
also generally arranged in more comprehensive groups, which 
have been variously named Sub-kingdoms, Groups, Divisions, 
Regions, Sub-divisions, &c. But as these are also of different 
extent and variously defined by botanists, we must refer to the 
several systems for particulars respecting them. 
The following table will include all the more important 
groups we have alluded to; those in more general use being 
indicated by capitals. 
1. SuB-KINGDOMS oR DIVISIONS. 
Sub-divisions. 
2. CLASSES. 
Sub-classes. 
Series. 
Cohorts or Alliances. 
3. ORDERS. 
Sub-orders. 
Tribes. 
Sub-tribes. 
4. GENERA. 
Sub-genera. 
Sections. 
5, SPECIES. 
Varieties. 
Races. 
Section 2. CHaARAcTERS, NOMENCLATURE, ABBREVIATIONS, 
AND SYMBOLS. 
Descriptive Borany is the art of describing plants in tech- 
nical language, so that they may be readily recognised when met 
with by those to whom they were previously unknown, who pos- 
sess a knowledge of the technical names of the different parts 
and organs of plants and of their various modifications. This 
subject is too extensive to be treated of here ; reference must 
be made to special treatises for this purpose ; but it is necessary 
for us to refer briefly to the Characters, Nomenclature, Abbre- 
viations, and Symbols of Plants. 
1. CHaracTers.—By the term character, we mean a list of 
