VI.] AGARICUS MELLSUS. 163 



Suppose, for example, a plantation presents the 

 following case. A tree is found to turn sickly and die, 

 with the symptoms described, and trees immediately 

 surrounding it are turning yellow. The first tree is at 

 once cut down, and its roots and timber examined, 

 and the diagnosis shows the presence of Agaricits 

 inelleus or of Trametes radiciperda, as the case may 

 be. Knowing this, the expert also knows more. If 

 the timber is being destroyed by the Traimics, he 

 knows that the ravaging agent can travel from tree to 

 tree by means of roots in contact, and he at once cuts 

 a ditch around the diseased area, taking care to include 

 the recently-infected and neighbouring trees. Then 

 the diseased timber is cut, because it will g€i worse 

 the longer it stands, and the diseased parts burnt. If 

 Agaricus melleus is the destroying agent, a similar 

 procedure is necessary ; but regard must be had to the 

 much more extensive wanderings of the rhizomorphs 

 in the soil, and it may be imperative to cut the moat 

 round more of the neighbouring trees. Nevertheless, 

 it has also to be remembered that the rhizomorphs 

 run not far below the surface. However, my purpose 

 here is not to treat this subject in detail, but to indi- 

 cate the lines along which practical application of the 

 truths of botanical science may be looked for. The 

 reader who wishes to go further into the subject may 



M 2 



