FILLING TREES 95 



ing the tree. Equally futile is the attempt which 

 is sometimes made to remedy chestnut trees which 

 have been completely hollow by the powdery red 

 heart rot. 



These general rules for the avoidance of unwise 

 expenditures in large tree repair projects must 

 be supplemented by a discussion of the comparative 

 importance of various kinds of cavities, and a 

 classification of them with reference to ease of ex- 

 ecution and certainty of success. 



As a preliminary of such classification, how- 

 ever, we must formulate a statement of the ends 

 aimed at in the filling of cavities, because our 

 decision as to the probability of success in filling 

 each type of cavity will depend upon the degree 

 to which the purposes of the filling can be attained 

 under the peculiar conditions presented by that 

 type of cavity. Briefly stated, holes in trees are 

 cleaned out and filled with these three purposes 

 in mind: First, to stop decay by removing all 

 the fungus. Second, to prevent the entrance of 

 fungi and insects by coating all exposed wood with 

 a protective dressing, by filling the cavity with 

 cement or asphalt, and by facilitating the healing 

 of the wound. The third purpose is to strengthen 

 the tree. 



These different purposes are attained with vary- 

 ing degrees of success. The first purpose can 

 sometimes be attained perfectly, especially in cases 



