54 
Trunk and Branches , or Stem . Thirdly, the 
Leaves ; and, fourthly, the Flowers or Seeds . 
The roo/ is that part of the vegetable which least 
impresses the eye ; but it is absolutely necessary* 
It attaches the plant to the surface, is its organ of 
nourishment, and the apparatus by which it imbibes 
food from the soil.— The roots of plants, in their 
anatomical division, are very similar to the trunk 
and branches* The root may indeed be said to be 
a continuation of the trunk terminating in minute 
ramifications and filaments, and not in leaves. 
When the branch or the root of a tree is cut 
transversely, it usually exhibits three distinct 
bodies : the bark, the wood, and the pith ; and 
these again are individually susceptible of a new 
division* 
The bark, when perfectly formed, is covered by 
a thin cuticle or epidermis , which may be easily 
separated. It is generally composed of a number 
of laminae or scales, which in old trees are usually 
in a loose and decaying state. The epidermis is 
not vascular, and it merely defends the interior 
parts from injury. In forest trees, and in the 
larger shrubs, the bodies of which are firm, and of 
strong texture, it is a part of little importance ; but 
in the reeds, the grasses, canes, and the plants 
having hollow stalks, it is of great use, and is ex- 
ceedingly strong, and in the microscope seems 
composed of a kind of glassy net- work, which is 
principally siliceous earth. 
This is the case in wheat, in the oat, in different 
species of equisetum, and, above all, in the rattan, 
the epidermis of which contains a sufficient quantity 
