The Buds. 85 



den changes in temperature. Axillary buds which have 

 not yet formed leaves, are clothed with similar scales. 

 Buds inclosed with scales are often called winter buds. To 

 more effectually shut out water, the scales are coated with 

 a waxy or. resinous layer in some plants, as the horse- 

 chestnut and balm of Gilead, and to protect them from 

 too sudden changes of temperature, they are lined in 

 other plants, as the apple, with a delicate cottony down.* 



129. Nature Provides very Early for the Next Year's 

 Growth in perennial plants. With the expansion of each 

 leaf, a tiny bud begins to form at its axil, destined if 

 need be to become a branch the following year. Some- 

 times, however, especially in very vigorous shoots, the 

 embryo buds at the axils of the earliest formed leaves 

 remain undeveloped. The more rapid the growth of the 

 shoot, the less developed, as a rule, are the lateral buds. 

 Cions (386) and cuttings (358) should not, therefore, be 

 taken from excessively vigorous shoots. 



130. Branches Develop from Lateral Leaf-Buds (132). 

 In trees and shrubs (woody perennials), the lateral buds 

 do not usually push into growth until the spring after 

 their formation, unless the terminal bud is injured. 

 Indeed, they may never push into growth. Some lateral 

 leaf-buds, especially those most distant from the terminal 

 bud, usually remain dormant, through want of light or 

 nutriment, and are overgrown by the enlarging stem the 

 following year. Such overgrown buds, stimulated by 

 destruction or injury of the stem above, sometimes push 

 into growth years after their formation. 



* A vertical section of the onion bulb may be used as a magnified illus- 

 tration of a bud as it appears in winter, and that of a head of cabbage, of 

 a bud unfolding in spring. 



