CH. v.] TRAMETES RADICIPERDA. 143 



undoubtedly living trees it can soon be shown that 

 they are very numerous and varied in kind ; hence it 

 will be necessary to make some choice of what can 

 best be described here. I shall therefore propose for 

 the present to leave out of account those diseases 

 which do injury to timber indirectly, such as leaf- 

 diseases, the diseases of buds, growing roots, and so 

 forth, as well as those which do harm in anticipation 

 by injuring or destroying seedlings and young plants. 

 The present chapter will thus be devoted to some of 

 the diseases which attack the timber in the trees which 

 are still standing; and as those caused by fungus 

 parasites are the most interesting, we will confine 

 our attention to them. 



It has long been known to planters and foresters 

 that trees become rotten at the core, and even hollow, 

 at all ages and in all kinds of situations, and that in 

 many cases the first obvious signs that anything is the 

 matter with the timber make their appearance when, 

 after a high gale, a large limb snaps off, and the wood 

 is found to be decayed internally. Now it is by no 

 means implied that this rotting at the core "wet- 

 rot," " red-rot," &c., are other names generally applied 

 to what is really a class of diseases is always 

 referable to a single cause ; but it is certain that in 

 a large number of cases it is due to the ravages of 





