NATURE OF PLANTS 99 



terially since these leaves are of service only during the winter, 

 and soon fall off after the opening of the bud. Consequently the 

 scars formed by the fall of these protective scales form a ring 

 (Fig. 73, r) each year about the stem which marks the position 

 of each successive bud. By counting the number of these rings 

 on a twig you can ascertain its age and observe the extent of 

 elongation during each season, just as the age and increase in 

 diameter is revealed by the annual rings of the wood. From 

 the twigs and branches may be read the life history of the plant, 

 the nature of the season, the competition experienced and the 

 fruit formed (Fig. y$, B). Buds are usually found singly in 

 the axils of the leaves and as a rule only a few that are favorably 

 situated as regards the light ever develop. The development 

 of the buds brings about the characteristic appearance or habit 

 of the plant. This growth is not controlled alone by the favor- 

 able position of the buds but also by the interaction or correla- 

 tion of all the growing parts. As a result in some trees we find 

 a single terminal bud that is larger and better developed than 

 all others. This bud will produce the longest shoots and con- 

 sequently such trees will have spire-like stems as in the spruces, 

 larches, etc. In other cases this same type of growth may con- 

 tinue for a time but eventually terminal buds of equal vigor will 

 be developed upon several branches and consequently equal 

 growths or diffuse types of branching will result as in the maples, 

 elms, etc. Buds that are not favorably located generally perish 



produces the next year a pear at a" and a lateral shoot reaching to 8 and 

 bud 7 at the same time only develops a leafy shoot reaching to 9. Buds 

 8 and 9 both produce fruit the ne-xt season (a' v , a Ti ) and short lateral 

 branches reaching to 10 and II. These buds during the present season 

 only formed leafy shoots. 



Buds are formed in the axils of all the leaves that appear on the shoots 

 of a season's growth, but notice that but few or none at all develop. 

 Some have a thrifty growth, others remain small and perish after one or 

 more years. This is true of the fruit. Some of the pears mature, as is 

 indicated by size of the scars, while others drop off after one or more 

 months. Note also the almost regular alternation in the production of 

 shoots bearing fruit and leaf shoots. Bud 6 is the only exception to this 

 succession. Observe that the branches assume different positions and 

 that the extent of the elongation of the shoot from year to year varies. 

 Can you explain these facts? 



