Treatment of Street Trees 117 



damage, systematic warfare should be waged against these 

 pests, the means of which are discussed in the next chapter. 



In street trees the opportunity for mutilation is so great 

 and the neglect so usual, that the tree surgeon will often be 

 called upon to exercise his knowledge and ingenuity in the 

 direction of mending old damage. 



Walking along the streets of any city one will find from 

 at least twenty-five to fifty per cent, of the trees in a dam- 

 aged condition. The principal cause of such damage is 

 probably the gnawing of horses and the careless treatment 

 of passers-by. The climbing irons of wire stringers and of 

 careless tree-pruners also frequently lead to abrasions of 

 the bark. Guy ropes attached to trees in building opera- 

 tions are a frequent cause of damage, unless properly pro- 

 tected by boards in such a manner as to properly distribute 

 the pressure and prevent laceration and bruising of the 

 bark. The piling of stones against the base of trees with- 

 out protection is also apt to result in bruises. 



The proper thing, of course, is to abstain entirely from 

 such use of trees. But since the casual damage done can 

 hardly be avoided by regulations, young trees, at least, 

 should be protected by suitable guards, until their bark 

 has become robust and less likely to become damaged. 



The accompanying illustrations, showing a variety of 

 guards as used in various cities of Europe and the United 

 States, have been borrowed from a Bulletin of Cornell 

 University Agricultural Experiment Station,^ and are self- 

 explanatory. 



The following remarks on these protecting devices are 

 taken from the same Bulletin. 



"The most primitive guard in use is a handful of branches 



' "Shade Trees" by W. A. Murrill, Bulletin 205, Cornell University 

 Agricultural Experiment Station, Ithaca, N. Y., 1902. 



