48 MORPHOLOGY OF STEMS. 



branches will l>c alternate ; when the leaves are opposite, and 

 the buds develop regularly, the: branches will be opposite. &c. 

 This holds in I'aet siilliciently to detenniiie and exemplify the 

 plan of ramification ; but, if entirely carried out, there would be 

 as many branches as leaves. This could rarely if ever be, even 

 in primary ramilieat ion. 



si. Non-development of Buds. Some of the buds are latent or 

 merely potential, that is. do not make their appearance : of those 

 which do appear only a part actually grow into branches : and 

 of these some are apt to perish at an early stage. In our trees, 

 most of the lateral buds generally remain dormant lor the first 

 season : they appear in the axils of the leaves early in summer, 

 but do not grow into branches until the following spring; and 

 even then only a part of them grow. Sometimes the failure 

 occurs without appreciable order; but it often is nearly uniform 

 in each species. Thus, when the leaves are opposite, there are 

 usually three buds at the apex of a branch ; namely, the terminal, 

 and one in the axil of each leaf; but it seldom happens that all 

 three develop at the same time. Sometimes the terminal bud 

 continues the branch, the two lateral generally remaining latent. 

 as in the I lorsecliestnut (Fig. 85) ; sometimes the terminal one 

 fails, and the lateral ones grow, when the stem annually becomes 

 tw r o-forked, as in the Lilac, Fig. 86. The undeveloped buds 

 do not necessarily perish, but arc ready to be called into action 

 in case the others are checked. When the stronger buds are 

 destroyed, some that would else remain dormant develop in their 

 stead, incited by the abundance of nourishment, wliieh the for- 

 mer would have monopoli/ed. In this manner our trees are soon 

 reclothed with verdure, after their tender foliage and branches 

 have been killed by a late vernal frost, or consumed by insects. 

 And buds which have remained latent for several years occasion- 

 ally shoot forth into branches from the sides of old stems, 

 especially in certain trees. 



85. .Most branches springing from old trunks, however, as in 

 Willows and Poplars, especially when wounded or pollarded, 

 originate from adventitious buds (77), which occur without 

 order. So also when accessory buds (7<>) develop into branches, 

 normal symmetry is more or less disturbed, as by contiguous 

 shoots standing directly over each other in Tartarean Honey- 

 suckle, or by a branch far out of the axil in Walnuts (Fig. 89) 

 and Honey-Locust. Fig. !(>. 



86. Exeiirreiit and Deliquescent Steins. Sometimes the primary 

 axis is prolonged without interruption, even through the whole 

 life of a tree (unless accidentally destroyed), by the continued 





