66 



Tlie mycelium oi' the rungus aliiiosl always produci's a vorj 

 characteristic mottled fan-like appearance in the bark, and ap- 

 pears to penetrate throngh the tissues of the bark but a short 

 distance, if at all, beyond this discolored area. The mycelium 

 also penetrates the sapwood very freely, when the disease reaches 

 as deep as the wo(jd, as it generally does sooner or later; but, 

 unlike its ett'ect in I lie bark, no pronounced discoloration is pro- 

 duced in the wood, and it is impossible to determine with the 

 unaided eye the approximate limits of the mycelium, as in the 

 case of the bark. 



In all efforts to control the disease without destroying the 

 tree, it is of course necessary to gouge out this disease infected 

 sapwood. The depth to which it is necessary to remove it can- 

 not at present be definitely stated, as insufficient time has 

 elapsed to demonstrate this point experimentally. Many cut- 

 tings, some with the sapwood partially removed from beneath 

 a lesion, and others with all of it removed, are now being watched 

 for results. However, in a diseased spot from three to four 

 inches in diameter apparently at least three annual layers of 

 ^^()(Ml ill the centre of the diseased s[K)( must be removed. 



or course where sapwood is cut, enormous numbers of minute 

 tubes, which conduct the crude sap from the roots through the 

 trunk and branches to the leaves, are severed, and, should the 

 cutting happen to have been done during warm, dry weather, 

 it often happens (hat one or more branches directly above the 

 ciit-ont area will show much Avilted leaves within an hour or 

 two. This is a direct and inevitable result of the suppression, 

 from any cause whatsoever, of a considerable portion of the sup- 

 [»ly of water for the leaves. 



Considerable careful judgment may at times have to be used 

 when making cuts of this nature, and occasionall}^ it nmy be 

 wise to remove one or more healthy lind)s, or perliaps to strip the 

 foliage partially from a branch situated just above a place where 

 nincli sapwood has been removed. This \\\\\ at least tend to pre- 

 vent wilting, which if excessive, may result in (lie sul>se([nent 

 death of the branch. 



(3). Preservation of exposed Avood from decay. 



If exposed surfaces of wood are left w itli no protective cover- 

 ing they soon become weathered, dried, checked, and easily in- 

 fected with fungi, causing decay of the wood, In the chestnntj 



