SHOOTS. 



71 



they do not need to be exposed to the light. Stems bearing 

 only scale leaves, therefore, hold no necessary light-relation, 

 and may be subterranean as well as aerial. For the same 



Fig. 62. A group of weeping birches, Bhowing tlie branching habit and the peculiar 

 hanging branchlets. The trunks also show the habit of birch bark in peeling off 

 in bands around the stem. 



reason scale leaves do not need to be separated from one 

 another, but may overlap, as in the buds referred to. 



Sometimes scale leaves occur so intermixed with foliage 

 6 



