V] EPICORMIG SHOOTS 39 



branch is removed by pruning, or broken off by wind, 

 the weight of snow, &c. Or it may be that the necessary 

 stimulus is supplied by the foliage being suddenly ex- 

 posed to better conditions of nutrition, as, for instance, 

 when a tree hitherto shaded by others is suddenly freed, 

 and its leaves more exposed to light and air, by the 

 felling of surrounding trees which prevented the access 

 of light. 



It is a common experience that Beeches, Elms, Limes, 

 &c., thus suddenly exposed, cover their by this time thick 

 and naked stems with what are called epicormic shoots, 

 in some cases here and there, in tufts, in others from 

 points so numerous that the whole stem is covered as by 

 bushy outgrowths. 



In most cases these epicormic shoots have sprung 

 from dormant buds, which were developed years ago when 

 the stem was a shoot, but which were never able to do 

 more than just keep their heads alive on the surface of 

 the thickening stem, and, in many cases, their tufted 

 origin is explained by their being traced to buds formed 

 in the axils of the bud-scales (Fig. 21). 



Similarly are to be explained the more or less rich 

 output of suckers from the base of the stem in such 

 trees as 



Black Poplar Lombardy Poplar Hornbeam 



Alder Maple Ash 



Oak Elm Scots Pine 



Birch Aspen White Poplar 



Robinia Spruce Silver Fir 



Larch Beech. 



These suckers or " gourmandizers " are frequently 

 stimulated to further outgrowth as the result of cutting 

 off the upper parts of a tree, or of the destruction of such 



