68 



A TEXT-BOOK OF BOTANY 



inner (younger) ones, and all the leaves protect the delicate 

 growing apex of the stem or the branch. There are what 

 are called leaf-buds and flower-buds, but only the former 

 will be considered here. 



29. Position of buds. In shrubs and trees the growth 

 of stem and branches is not continuous, but is interrupted 

 during the winter. Preparatory to this 

 interruption a bud is formed at the end of 

 each growing axis, and is called the termi- 

 nal bud (Fig. 66). When it opens the fol- 

 lowing season it continues the growth of 

 the stem or branch. Buds are formed also 

 in the axils of leaves, usually one bud in 

 an axil, and hence they are called axil- 

 lary buds (Fig. 66). When they develop 

 they form new branches. When the ter- 

 minal buds are stronger than the axillary 

 buds, the main stem or branches continue 

 to elongate year after year; but if the 

 axillary buds are stronger, the growth of 

 the new branches may replace that of the 

 stem from which they arise. For exam- 

 ple, in the common lilac the two buds in 

 the axils of the uppermost opposite leaves 

 develop branches, the terminal bud be- 

 tween them not continuing the growth 

 of the axis, and often not even being 

 formed. Hence the lilac bush is charac- 

 terized by its forked branching, each axis appearing to end 

 in a pair of branches. Axillary buds do not all develop into 

 branches by any means, but any of them may do so under 

 certain conditions. If the terminal bud is injured or is fee- 

 ble, the axillary bud or buds nearest to it will be more 

 likely to develop branches; and if the upper axillary buds 

 are injured, the next lower ones will develop, and so on 



FIG. 66. Scaly buds 

 of hickory; termi- 

 nal one strongest; 

 lateral ones axil- 

 lary as shown by 

 the leaf scars. 

 After GRAY. 



