Functions of Vegetables . 20f 
meal classification, as well as many curious topics for 
physiological inquiry. 
The branches of trees or shrubs, which constitute a 
minuter division of the trunk or principal stem of the 
vegetable, may be regarded as a new order of stems, 
whose roots are attached to a ligneous base, and thus 
form the necessary communication between the leaves 
and the source of nourishment. 
The general aspect of a plant depends, in a great 
measure, on the distribution of the branches, as they 1 
spring from the trunk in a spiral direction, opposite to 
each other, in whorls, disposed irregularly, or from two 
sides of the trunk only, and form with it more or less 
acute angles. On the same plant the branches are ob- 
served to be arranged in very different, and almost op- 
posite directions. In a large tree the lower branches 
are bent towards the earth, some spread out horizon- 
tally, and those towards the summit of the tree rise- 
nearly in a perpendicular direction ; but the disposi- 
tion of the whole is such that the action of the air and 
light, of so much importance to the health and vigour 
of the vegetable, may be the least interrupted. Influ- 
enced by the same cause, a plant in a shady. place in- 
clines all its branches to that side where the action of 
air and light is most powerful ; and plants, confined in, 
a hot-house, turn all their leaves and branches towards 
that side from which the light proceeds. 
According to Schabol, as quoted by Mirbel, five 
different kinds of branches may be distinguished in 
fruit-trees, — a distinction of no small importance in 
their culture and management. In the first kind the 
surface is smooth, the vessels run in a straight direc- 
tion, and are easily separated y they bend without 
