TREE FORMS IN WINTER 247 



pale yellowish-green, which represents a still earlier stage. 

 This silveriness of the bark is not an invariable mark of the 

 birch. In old or weather-beaten specimens, the bark grows 

 split and blackened, and the whole surface covered with dark 

 callous scars. The birch's slender catkins, like the stouter 

 cones of the alder, are much sought in later autumn by 

 linnets and redpolls, which pick them to pieces for the seeds. 

 The ground beneath the boughs is often thickly strewn with 

 the yellowish scales ; and by the time that the last yellow 

 leaves have flown down the November blasts, the catkins are 

 usually almost gone. 



Birches love a bleak, upland situation, or a barren, sandy 

 soil ; and in their higher and rockier haunts they are con- 

 stantly found in company with the mountain-ash or rowan- 

 tree. Often this is clipped by the winds into a straggling 

 and stunted shrub ; but in sheltered situations it sometimes 

 becomes a large and rounded tree of thirty or forty feet 

 high. It is most easily recognised in winter by its smooth 

 and glossy bark of pale grey. The tracery of its twigs and 

 branches is sparse and blunt, so that it forms a very decided 

 contrast with the fine filaments of the birch. Young rowans 

 are often light and graceful, as they spring in the shelter of 

 some Welsh nant or North country clough ; but before 

 many winters pass over them the buffeting of the wind makes 

 them one-sided or cramped of growth, and often dispro- 

 portionately thick in trunk and bough. They run into stout, 

 yet supple curves, which, with the smoothness and colour 

 of the bark, gives the tree an appearance of being built of 

 india-rubber. The rowan has not the birch's power of 

 growing delicate sprays in the teeth of the moorland winds ; 

 and its leaves being large and compound, it does not require 

 so abundant a growth of twigs as are necessary for the small 

 leaves of the birch. 



