214 MASS. EXPERIMENT STATION BULLETIN 170. 



trees should be done without the use of spurs. Most of our inteUigent and 

 thoughtful foresters and tree wardens never allow them to be used. 



Ice is responsible for much disfiguration of trees which cannot easily 

 be prevented. It affects more particularly such soft-wooded trees as the 

 white maple, and greatly mutilates them by breaking down their limbs. 



Posting advertisements on trees on country roadsides is another objec- 

 tionable practice, but this is prohibited by law in Massachusetts. (See 

 page 263.) A great many roots are injured and destroyed by the 



Fig. 87. — Trunk of au elm tree, showing old trunk and new formation of roots. 



laying of gutters and curbs, sewers, water and gas pipes, telephone con- 

 duits and catch-basins, but at present this seems to be unavoidable. 



Earth Fillings around Trees. 

 The remodeling and regrading of streets, lawns, etc., often necessitate 

 filling in around trees. These earth fillings are usually fatal to trees, no 

 doubt owing as often to the effects of the earth on the bark as to the lack 

 of air to the roots from the deep covering of the soil. We have seen trees 

 growing on a bank with one side of the root system and part of the trunk 

 covered with soil. Those parts covered with soil gradually died, and 

 finally the whole tree died. The maximum depth of soil around the 

 trunk was not more than 8 inches, but the roots were covered for 18 to 

 20 inches. The soil used for refilling was of a fine texture, — undoubtedly 



