46 SOUTH AFRICAN BOTANY 
undeveloped branch, and consists of a stem structure in 
which the internodes are very short, and a number of 
leaves packed tightly together since the nodes are so 
close to each other. Such a bud is called a TERMINAL 
Bup. Similar buds occur in the axils of the leaves and 
are hence called AxtLLARY Bups. When these develop 
a new branch is produced. Axillary buds can remain 
dormant for a number of years, and branching on the 
older portions of trees is caused by the development of 
these hitherto dormant buds. 
Buds form very conspicuous objects on deciduous trees 
in winter, and especially in spring, although they can 
be found on plants at all seasons. In winter the buds 
very often develop protecting scale leaves to prevent 
loss of heat and moisture. These scale leaves may con- 
tain resinous secretions, or be covered with hair. As the 
bud unfolds these scale leaves fall off, leaving very dis- 
tinct scars. The age of a branch can be told by count- 
ing the number of such scar zones between its point of 
insertion in the main stem and its apex. 
If a bud is developed on other parts of the plant be- 
sides the apex of a stem or the axils of leaves, it is 
called an ADVENTITIOUS Bup. Such adventitious buds 
may be found on roots or on leaves, e.g. begonia. 
Sometimes a whole plant consists of a bud, e.g. the 
cabbage plant, and in this case food is stored in the 
closely packed leaves. 
The buds of different kinds of deciduous trees are very 
characteristic and’ serve to identify the tree even in 
winter when leaves and flowers are absent. 
27. Microscopic Structure of the Stem.—If we cut a 
