Formation and Functions of the Btuls. 



CHAPTER VII. 



THE STRUCTURE AND FUNCTIONS OF THE VARIOUS PARTS OF 

 GROWING TREES. 



The Formation ami I'tmHinn* f tin' 



232. Iii common deciduous trees, there begins to form, in mid- 

 summer, in the axils of the l<-:ive-, a little cellular mas-. 

 communicating with a medullary ray, partly covered by 



the bark, and usually protected by imbricating scales. 

 From these buds or germs, the leaves and blossoms of the 

 next season are to grow. The leal-buds are usually more 

 sharp and slender than the llower-buds, a circumstance 

 quite noticeable upon the elm, and upon many fruit trees. 



233. The end of a twig is dln-ni/* terminated by a bud, 

 which advances as the t \\ ig extends in length, by {In- 

 formation of new cells within. Tivcs and their branches 

 increase in length and height by the lormatioii of i 

 new cells under the terminal bud, and eln^:ite only 

 during the season of active vegetation, in spring and 

 early summer. The annexed engravings, fn.m K>-m;i-s- 

 ler, represent sections of four kinds of buds. The first is 

 a double one of leaf and flower, and the fourth is a llower- 

 bud only. It will be seen that the rudiments of the future 



2. 3. 4. 



40. Sections of Buds : 1. The Pmc ; 2. The Bird Cherry ; 3. The Oak ; and 4 The 



Aspen. 



