56 



STRUCTURE OF BUD-SCALES 



[CH. 



The cork-layers found in most scales, as well as hairs 

 and resin, are useful in preventing undue loss of water, 

 and the removal of such scales usually involves the desic- 

 cation and death of the young leaves inside, though 

 differences exist with regard to the endurance of the de- 



Fig. 36. 



Fig. 37. 



Fig. 36. Plan-diagram of a bud of Magnolia, the scales of which are 

 closed stipules, enveloping the distichous conduplicate leaves : the edges 

 of the latter directed towards the axis of the shoot. B leaf in the axil of 

 which the bud is situated. 



Fig. 37. Diagram of bud of tne Plane in plan. Between the axis 

 and the subtending leaf, the bud is composed of successive envelopes 

 of closed stipules, between the inner of which lie the distichous revolute 

 leaves. 



nuded buds of different species. For instance, the denuded 

 buds of the Beech endured far longer than those of the 

 Oak, because the leaves of the former are covered with 

 silky hairs, and, for similar reasons, the buds of the Horse- 

 chestnut withstood desiccation very well. 



The following classes of protective scales were made 

 out. In the Spruce, Oaks, Willows, Rhododendron, &c. 

 the scales have a markedly thickened cuticle. Most Coni- 

 fers, the Black Poplar, &c. have similarly protected scales, 



