86 THE APPLE-TREE 



not Started to decay in the meantime, the place is safe, 

 but too often invasion has begun before the process is 

 complete, the rot disease finally extends to the heart of 

 the tree, causing it to become hollow. If the center of 

 the wound falls in, the callus cannot cover it, and an open 

 sore remains. In these cavities birds may sometimes 

 build. 



Therefore there are two points for the surgeon to 

 consider in respect to the wound itself — whether it is 

 so placed on the tree that the callus forms readily; 

 whether the wound is kept healthy during exposure. 



All ragged tissue being removed, deep-wound sur- 

 faces should be kept aseptic. For ordinary cases, 

 white-lead paint with plenty of linseed oil is a good pro- 

 tective from the germs of decay. On old wood, no longer 

 active, creosote is good, perhaps followed by coal-tar. 

 Usually, however, paint is quite sufficient. Small ex- 

 posures usually receive no dressing. When the fresh 

 surface wood is exposed by removal of bark, it is neces- 

 sary to keep the tissue from drying out, and antiseptics 

 are usually not applied. Bandaging with cloth is the 

 usual practice, after the wound is cleaned and trimmed. 



The repairs fall into two classes, — those that require 

 merely removal of injured parts and treatment of the 

 wounds, and those that demand the ingrafting of new 

 wood. 



We have learned, in the discussion of pruning, that 

 long projecting ends of severed branches do not heal. 

 The branches to be removed should be cut back close 

 to the larger branch or to the juncture with another. In 

 repairing injured trees, all projecting parts that do not 

 have life in themselves must be removed. All wounds 



