164 THE CULTIVATED EVERGREENS 



obtained. Such treatment is usually rendered necessary 

 through neglect of small injuries and especially through the 

 leaving of branch stubs, by way of which fungi reach the heart 

 of the tree and there initiate destructive rots. The full details 

 of this branch of the subject cannot be entered into here, but 

 they are given in readily available form in the publication 

 mentioned below.* The fundamentals, however, may be 

 summarized as follows: 



All diseased wood must be removed, together with a certain 

 amount of apparently healthy tissue. In doing this it will be 

 necessary to cut away a portion of the bark, but the hole made 

 should be no larger than is absolutely essential. The edge 

 should be trimmed and the opening pointed above and below 

 to facilitate healing over. The exposed sapwood and bark 

 should then be sealed with a coating of shellac and the re- 

 mainder of the exposed wood sterilized. For this purpose, 

 creosote is one of the best preparations, but it must not be 

 used on the bark. The whole shellacked and creosoted surfaces 

 are then covered with a thick coating of tar or asphaltum. 

 The bottom of the cavity must be so shaped that water will 

 run out readily and this will sometimes necessitate the filling 

 up of this part of the cavity to give the requisite slope. 



This completes the essential operations in the treatment 

 of such wounds. Regular inspections should be made at least 

 biennially and if there is any cracking of the waterproofing 

 material a fresh coat should be applied. An open cavity is 

 much better for this reason, in that it allows one to make 

 thorough inspections from time to time. From an ornamental 

 standpoint, however, it may sometimes be advisable to fill 

 such cavities. For this purpose, asphaltum or cement are 

 most commonly used. The opening to the cavity may also 



* Collins, F. J. Tree-Surgery. U. S. Dept. Agr. Farmers' Bull. 173 : 1-29. 1920. 



