Growth and Form Development 



II 



ing in diameter by additions, 

 grows into a branch; new 

 branchlets start from buds 

 along the length of the mother 

 shoot, the daughter shoots 

 forming side branches, and by 

 repeated ramifications, gradu- 

 ally from year to year, the 

 crown is built up, character- 

 istic in form and following 

 well-known laws, typical for 

 each species. 



One important fact to be ob- 

 served in this process of build- 

 ing up a crown is, that not all 

 the buds which are formed on 

 the twig develop into shoots; 

 some remain undeveloped or 

 dormant as buds, some are 

 frozen, some dried up, some 

 eaten or broken off; and even 

 of the shoots which have been 

 developed not all grow into 

 limbs or branches: many are 

 lost sooner or later by causes 

 similar to those which destroy 

 the buds, and by the with- 

 drawal of light and food, as the 

 upper portions of the crown 

 develop and cut off from the 

 less favorably placed portions 

 the necessaries of life. Just as 

 in the animal world the struggle for existence necessitates 



Fig. 4. — Bud Structure (Maple), 

 A, longitudinal section through 

 branch lip; g, end bud; s, lateral 

 buds; /, scars of leaves of last sea- 

 son. 5, cross section through bud, 

 showing folded leaves in center and 

 scales surrounding them. 



