42 PRACTICAL TREE REPAIR 



desirable because by immediate attention the size 

 of the wound can often be greatly diminished, 

 and its healing can be correspondingly facilitated. 

 This is by virtue of the fact that when bark is torn 

 from a tree it is the mucilaginous cambium layer 

 which lets go. Some of the cambium cells come 

 off with the bark and some remain on the surface 

 of the wood. If a suiEcient number remain on 

 the wood, and if they do not dry out, they have 

 the power of growing and of developing new bark- 

 producing cells, which rapidly replace the detached 

 bark. It is obviously desirable to take advantage 

 of this recuperative power of the cambium. 

 When a tree is barked the wound must be pro- 

 tected from the sun and wind without a moment's 

 delay, by replacing the torn bark or otherwise 

 covering it. A dressing for the wound must next 

 be secured. For fresh wounds nothing is better 

 than soft or liquid grafting wax. A mixture of 

 clay and cow-dung is the second choice, with 

 shellac and paint to choose from if neither of the 

 preceding materials is at hand. Tar should not 

 be used, as it frequently kills the cambium it is 

 supposed to protect. 



In preparing the wound for the dressing all 

 detached bark must be cut away with a sharp 

 knife, care being taken to cut into the wood as 

 little as possible. The dressing should be flowed 

 on with a soft brush, or smeared on in such a way 



