THE VEGETATIVE ORGANS OF PLANTS. 263 
mates, have branching stems, originating in the following 
manner: As the principal or main stem elongates, so that 
the leaves arranged upon it separate from each other, 
we may find one or more side or axillary buds at the point 
where the base of the leaf or of the leaf-stalk unites with 
the stem. From these buds, in case their growth is not 
checked, side-stems o¥ branches issue, which again sub- 
divide in the same manner into branchlets. 
In perennial plants, when young, or in their young 
shoots, it is easy to trace the nodes and internodes, or the 
points where the leaves are attached and the intervening 
spaces, even for some time after the leaves, which only 
endure for one year, are fallen away. The nodes are mani- 
fest by the enlargement of the stem, or by the scar covered 
with corky matter, which marks the spot where the leaf- 
stalk was attached. As the stem grows older these indi- 
cations of its early development are gradually obliterated. 
In a forest where the trees are thickly crowded, the 
lower branches die away from want of light; the scars 
resulting from their removal are covered with a new 
growth of wood, so that the trunk finally appears as if it 
had always been destitute of branches, to a great height. 
‘When. all the buds develop normally and in due propor- 
tion, the plant, thus regularly built up, has a symmetrical 
appearance, as frequently happens with many herbs, and 
also with some of the cone-bearing trees, especially the 
balsam-fir. 
Latent Buds.—Often, however, many of the buds re- 
main undeveloped either permanently or for a time. 
Many of the side-buds of most of our forest and fruit trees 
fail entirely to grow, while others make no progress until 
the summer succeeding their first appearance. When the 
active buds are destroyed, either by frosts or by pinching 
off, other buds that would else remain latent, are pushed 
into growth. In this way, trees whose young leaves are de- 
stroyed by spring frosts, cover themselves again after a 
