OPENING OF BUDS 205 
In plants, like annuals and those that live in the tropics, the 
buds usually have no protective scales and are called naked buds. 
Scaly buds are characteristic of plants which 
must pass through seasons that are unfavor- 
able for growth, and may be considered a 
device for maintaining partially developed 
stem portions in a protected state, and in 
readiness to assume rapid growth at the 
opening of the growing season. 
Fic. 184.—Plum 
branch showing regions 
of different ages as in- 
dicated by the scars re- 
sulting from the falling 
away of the bud scales. 
Described in text. 
Opening of Buds. — 
The bud scales are forced 
open by the growth of 
the young shoot within. 
The resumption of 
growth by the parts en- 
closed is first shown by — yg. 183. — Flower 
the swelling of the bud. bud of the Pear, in 
When the young shoot which the flowers are 
resumes growth at the Pushing the scales 
beginning of the grow- apart ond compen 
; : ., of the bud. After 
ing season, it grows with Bailey. 
remarkable rapidity and 
in a few days pushes out of its scaly cover- 
ing. (Fig. 183.) After the shoot has es- 
caped, the scales usually fall off, leaving a 
scar about the branch at their place of at- 
tachment. The bud has now disappeared 
and in its place there is a new growth bear- 
ing leaves or flowers, or sometimes both. 
The scars left by the scales remain until 
the bark is sufficiently developed to obscure 
them, and serve to indicate the age of the 
different regions of a branch. In Figure 
184, the portion beyond the scar (a) is the 
last season’s growth. The portion between 
(a) and (b) is two years old, and the por- 
tion between (b) and (c) is three years of 
age. Thus the age of a given region of 
3 branch is indicated by the scars on the branch as well as by 
the annual rings in its woody cylinder. 
