H2 TREE WOUNDS AND DISEASES 



and not only so, but, by shutting up the pores 

 of the wood and displacing air and water, 

 the lifetime of the timber is greatly increased. 

 Other substances, such as corrosive sublimate 

 and copper sulphate, have been used, but 

 nothing, either on account of efficacy or cheap- 

 ness, can surpass carbolineum or creosote. 



In the case of young thinnings of pine plan- 

 tations, the trees, if used as fencing, will in the 

 case of Scotch pine last about five years, and of 

 larch eight years ; whereas, if treated with 

 creosote and fungoid attacks prevented, the 

 lifetime will be extended to nearly treble the 

 period. 



Forest trees, under certain conditions, are 

 sometimes damaged by the too pressing atten- 

 tions of such undergrowth as the woodbine and 

 ivy. The ivy does most damage in young 

 plantations of larch and hardwoods, and, if the 

 growths are not kept in check, the annual woody 

 layers become less and less, and ultimately the 

 tree dies out altogether. This is brought 

 about by the restricted sap ascent, which causes 

 the leaves to turn thin and pale and the annual 

 shoots to gradually lose their vigour, and thus 



