THE SOFTWOODS 183 



remarkable degree among all the other light- 

 demanding trees, the two characteristics of rapi- 

 dity in growth upwards and thinness of foliage. 

 Their hardiness against frost, their rapidity in 

 growth, and the comparative lightness of the 

 shadow they cast around them, qualify them 

 excellently, and especially the birch, for acting 

 as a nurse to species like oak, ash, chestnut, beech, 

 &c., in places where they are likely to be 

 nipped and damaged by late frosts in spring. 

 When once these kindly offices have been per- 

 formed, however, birch and aspen should be 

 at once cut out, else they only interfere with 

 the growth and the healthy normal development 

 of the more valuable young trees desired as the 

 crop. Even then much trouble is often caused 

 by the stool-shoots of the birch and the suckers 

 thrown up in profusion by the aspen, as both 

 trees are strongly reproductive when thus felled. 

 It is often wonderful how long a hold on life 

 the roots of aspen seem to have ; for the suckers 

 often spring up very freely when mature crops 

 of timber are being felled, even though it be 

 long years since the aspen have been cut out. 

 And such stoles can prove noxious weeds before 



