ABNORMAL TISKI 



137 



coalesce eventually into a single stem (Fig. 55). Asa rule one 

 of the stems grows slowly and eventually dies. One of the double 

 leaders should be removed in cleaning the young plantation, 

 but if previously it has been overlooked it should be removed in 



the thinnings. If not removed before 

 it is about four inches in diameter, 

 then, in the case of conifers, owing 

 to slow occlusion decay will certainly 

 affect the wood and will infect the 

 remaining sterns also. If no leaders 

 are removed, their united bole be- 

 comes a breeding-place for insects. 

 Kven if one of the leaders is removed 

 the remaining stem will, when 

 mature, be swollen at the base and 

 probably unsound. It is therefore 

 best to remove the plant entirely, in 

 the case of conifers. 



Fii_ r . :"). Lower part 

 of an old stem. Its 

 swollen b;i<e denotes 

 either double heart- 

 wood or red-rot. 



Fi-. .'<;. Union of three leaders 

 into one stem, while two other 

 branches have also coalesced 

 with the main stem. 



In young plants, double leaders often result from 

 injuries to their original leading shoots by game, and less 

 frequently from those by insects or fungi; also to the 

 destruction of the terminal bud by birds, hail, wind or late 

 frost. As plants are specially liable to these dangers in 



