CHAPTER V. 



DISEASES OF TIMBER. 



Trametes radiciperda. 



Having now obtained some idea of the principal 

 points in the structure, functions, and varieties of 

 normal healthy timber, we may pass to the con- 

 sideration of some of the diseases which affect it. 

 The subject seems to fall very naturally into two 

 convenient divisions, if we agree to treat of (i) those 

 diseases which make their appearance in the living 

 trees, and (2) those which are only found to affect 

 dead timber after it is felled and sawn up. In reality, 

 however, this mode of dividing the subject is purely 

 arbitrary, and the two categories of diseases are linked 

 together by all possible gradations. 



Confining our attention for the present to the 

 diseases of standing timber — ue, which affect 



