104 THE BOOK OF FORESTRY 



sitica. The spores of this fungus are carried by wind 

 or upon the feet of birds and finding lodgment in a 

 wound in the bark of a chestnut, start to grow. The 

 fungus develops in the inner bark and kills the tree by 

 girdling it, thus cutting off the sap supply. No remedy 

 for this disease has yet been found and although it is 

 not spreading as rapidly as when it was discovered in 

 1905, it is still killing this valuable species in large 

 numbers. The total loss at present has been estimated 

 to be in excess of $25,000,000. 



Another fungus disease which was imported from 

 Europe is the white pine blister rust which attacks 

 small pine trees. This fungus has caused much 

 trouble but is believed to be under control. It passes 

 part of its existence upon the currant and gooseberry 

 and if all the infected pines are torn out and burned 

 and the same treatment is administered to the berry 

 bushes within three or four hundred feet of the 

 plantation the remainder is likely to be safe. 



The influence of the saprophytic fungi those that 

 attack only dead trees and timber must really be con- 

 sidered beneficial, for it is owing to their action that 

 the trees and plants are so soon gotten out of the way 

 and their substance is again returned to the earth to 

 nourish the next generation of trees. 



As in a community of people, the loss in a forest 

 is greatest in childhood, least during middle life, and 

 then gradually increases with age. A forest is con- 

 tinually fighting against these agencies and when we 

 realize how the various tree species have survived 

 throughout the countless centuries, the marvelous 

 structure of a tree with its ability to resist and over- 

 come these many agencies becomes apparent. "We 

 realize that the tree bears the same relation to the 



