INJURIES TO SHADE-TREES 157 



many cases, no fine will compensate for the damage done, 

 because in a few minutes a horse may destroy a tree worth 

 hundreds of dollars, and which no amount of money can 

 replace. 



Trees Must Have Guards. In spite of the greatest care, 

 horses will sometimes bite trees ; and the only way to make 

 it impossible for them to do so, is to place guards around all 

 trees. On our public streets no tree is safe from the day of 

 planting until the time of maturity. I have seen trees com- 

 pletely ruined a few hours after they were set out, by the 

 horse of the grocer or butcher, who stopped to make some 

 deliveries. The only thing left to do was to set out new 

 ones in their place. When a larger tree, six or eight inches 

 in diameter, is barked, it cannot be so readily replaced. It 

 is left to grow in its injured state. In case the strip of bark 

 removed by the horse is small, the resulting wound may 

 heal, if a box is placed around the tree to protect it from 

 further injury. When a tree is badly bitten or is exposed to 

 successive mutilations, the bark of the growing tree never 

 covers up the scar so made, and the tree becomes irrepar- 

 able. 



As the tree grows, successive annual layers of wood are 

 added, and its diameter is increased. The portion of the 

 tree that has been stripped of bark does not receive this 

 new growth ; but the wood is deposited in a thick roll around 

 the edge of the wound. The exposed wood dries, checks, 

 moisture causes it to rot and form a fertile field for fungus 

 growth and the entrance of borers. After a while the decay 

 is carried to the heart of the tree, and sooner or later it dies. 

 The first cause of the decay and death of many of the trees 

 annually removed from public streets may be traced to the 

 mutilation of the trunks by horses. 



