SHADE TREES. 



171 



and other injuries which are not followed by proper treatment at the 

 time. 



The treatment of cavities naturally involves some expense, but if a 

 tree is of any value it is worth treating, even though its value may be 

 sentimental in nature. There are many trees which to the casual observer 

 would appear to be of little consequence, but the associations connected 

 with them may be highly cherished. Then, again, the location is often 

 important. A tree may furnish shade which cannot be dispensed with, 

 and even if old and decayed it is often more satisfactory to treat it than 

 to wait for a new tree to grow. 



The rationale underlying the cleaning and filling of cavities is similar 

 to that in dentistry. If the work is properly done, and if antiseptic con- 

 ditions are secured, the length of a 

 tree's hfe may be extended. 



For centuries trees have been 

 treated in various ways. Cavities 

 have been filled with wood, brick, 

 stone, cement and other sub- 

 stances, but as a rule much of 

 this earlier work was very crude 

 in nature, and has accomplished 

 little or nothing toward the pre- 

 vention of decay. During the past 

 few years, however, more scientific 

 attention has been given to the 

 treatment of decayed cavities in 

 trees, and many good examples 



may be seen here and there, although it must be confessed that as 3'et 

 the work is in more or less of an experimental stage. ^ 



As has been said, the object of treating decayed cavities is to prevent 

 further decay and to prolong the life of the tree; but there is no particular 

 reason why people should spend one or two thousand dollars on a single 

 tree for repair work when it is possible and certainly more reasonable to 

 transplant a larger and better one for two or three hundred dollars. 



The first step in the treatment of cavities is to remove all decayed and 

 infected tissue, which is done by a thorough cleaning out of the cavity. 



Second, to treat antiseptically all the exposed tissues which are sus- 

 ceptible to decay, preventing further disintegration. The disinfecting 



' The writer's first attempt to establish a course covering shade-tree management was in 1895 

 although the research work concerning shade-tree problems antedated this period. At that time 

 there was little material of a reliable nature at hand touching upon the many shade-tree problems 

 which were continually coming up, and it was practically impossible to organize a course of study 

 relative to the subject which would be of any great practical, scientific or pedagogical value. It 

 was, therefore, apparent from the first that an extensive course of study covering this subject, 

 to be of practical value, would require a scientific basis. However, the numerous investigations 

 carried on during recent years relating to shade-tree problems have placed this subject on an 

 entirely different basis, although there is still great opportunity for further research work along 

 these lines. 



Fig. 35. — Longitudinal section of 

 limb, showing method of bolting. 

 B, bark; X, wood; R, bolt; W, 

 washer; C, cement. 



