132 PRACTICAL COURSE IN BOTANY 
145. Terminal and axillary buds. — Notice the large bud 
at the end of a twig of hickory, sweet gum, beech, cotton- 
wood, etc. This is called the terminal bud because it ter- 
minates its branch. Notice the scars left by the leaves of 
the season as they fell away, and look for small buds just 
above them. These are lateral, or axillary, buds, so called 
because they spring from the axils of the leaves. How 
many leaves did your twig bear? What 
difference in size do you notice between 
the terminal and lateral buds? 
146. The leaf scars.— Examine the leaf 
sears with a hand lens, and observe the 
number and position of the little dots in 
them. Ailanthus, varnish tree, sumach, 
and China tree show these very distinctly. 
They are called leaf traces, and mark the 
points where the fibrovascular bundles 
from the leaf veins passed into the stem. 
eee a Look on the bark, or epidermis, for lenticels. 
t, terminal bud: az, 147. Bud scales and scars.— Notice the 
axillary buds; Js, leaf stout, hard scales by which the winter buds 
scars; tr, leaf traces; 
i, lenticels ; rs, ring of are covered in most of our hardy trees and 
i: eleanor shrubs. Remove these from the terminal 
one of your specimen, and notice the ring 
of scars left around the base. Look lower down on your 
twig for a ring of similar scars left from last year’s bud. 
Js there any difference in the appearance of the bark above 
and below this ring? If so, what is it, and how do you ac- 
count for it? Is there more than one of these rings of scars 
on your twig, and if so, how many? How old is the twig 
and how much did it grow each year? Has its growth been 
uniform, or did it grow more in some years than in others? 
148. Arrangement and use of the scales. — Notice the 
manner in which the scales overlap so as to ‘ break joints,’ 
like shingles on the roof of a house. Where the leaves are 
opposite, the manner of superposition is very simple. Re- 
