BUDS AND LEAF ARRANGEMENT. 47 



section of the bud brings to view the young leaves, crowded on 

 the stem, and overlapping its growing point. As the bud 

 expands, the protective scales, which must be regarded as the 

 lowest leaves of the shoot, fall off, and, as the internodes between 

 them do not elongate, leave behind narrow scars, which form a 

 band of ridges round" the stem, marking the commencement of 

 the year's growth. 1 Development of these internodes would serve 

 no useful purpose, but simply give a long piece of bare stem. 

 The remaining internodes elongate, and in the summer the shoot 

 will be found bearing about three pairs of large leaves, and termi- 

 nated by a large bud for next year. It may be noted here that 

 large leaves are always borne in small numbers. Overcrowding 

 would result from the presence of many, and the access of air and 

 light would be hindered. In a well-developed branch of horse- 

 chestnut the growths of several years can be distinguished by 

 noticing the successive bands of scars left by the bud scales of 

 different seasons. After a certain time, however, the scars are 

 obliterated by formation of bark, &c We may also notice 

 in such a branch the large heart-shaped scars of the ordinary 

 leaves (p. 43). Within each scar are seven small rounded eleva 

 tions, following the lower curve. These are the ends of the 

 vascular bundles that entered the leaf. 



Besides terminal buds we have axillary bud*, quite similar in 

 structure, and developing into lateral shoots (figs, 2, 4, and 5 A). 

 If every leaf-axil gave rise to a shoot which elongated, it is clear 

 that branching would follow the leaf arrangement. This, however, 

 is not the case. Sometimes buds are only developed in some of 

 the axils, and again many buds either die or remain undeveloped 

 or dormant. Examine once more the horse-chestnut. Two large 

 axillary buds will be seen near the end of every present or 

 current year's shoot. • Other dormant buds will be seen as little 

 brown bodies in the axils of the older leaves. This non-develop- 

 ment of many buds is of considerable importance. In the first 

 place, overcrowding is prevented, and then, should the first 

 shoots be blighted from any cause, as by a return of severe 

 weather in the spring, they can be replaced by growth of the 

 dormant buds. It may happen, as a regular thing, that the 

 terminal bud dies. If, as in mistletoe, the leaves are borne in 

 opposite pairs, the axillary buds of the last two grow vigorously, 

 and as the dead end of the parent stem is very small, it appeals 

 to have forked. This is false dichotomy (p. 24). It also occurs 

 in many branches of the lilac. A shoot from this plant generally 

 exhibits at its end a pair of vigorous lateral buds, between which 

 is a small terminal bud. This last sometimes grows on, and pro- 

 1 Such bands are very beautifully seen in the beech. 



