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has the additional misfortune of attracting lumbermen and nuts 
gatherers. If it escapes winter injuries to its trunk, the spring 
storms are sure to break the smaller branches and abrade the 
surfaces of the larger limbs ; if it is not disfigured by ae green 
fly and twig-borer during summer, it is sure to be mutilated by 
Fic. 19. The trunk of an infected nursery tree, shown natural size. 4, B and C 
are views from different directions. The point of infection in each view is shown at 
a, the area killed by the fungus last year at 4, and the development early in May of 
this year at c. Three days after this figure was drawn the girdling was complete. 
savage hordes of small boysin autumn. Even the ubiquitous 
squirrel may spread the disease with tooth and claw while cutting 
off ripe burs and racing up and down the trunks ; while every 
bird and insect that rests upon an infected spot is Hable to carry 
the spores upon its feet or body to other trees. Mice, voles and 
rabbits often make wounds about the base of a tree and carry the 
spores in their fur. All during the growing season spores are 
being developed in countless numbers, and these are liable to fall 
into even the slightest abrasions of the bark and germinate. 
The treatment of a disease of this nature must, of course, be 
almost entirely preventive. When once allowed to enter, it 
cannot be reached by poisons applied externajly, nor can the 
spores, which issue continuously and abundantly through erup- 
