SHADE TREE AND TIMBER DESTROYING FUNGI. 213 



An injury resulting from this kind of fractures leaves a long 

 and slivered end some distance from the point where healing 

 takes place. It must be a number of years then before the 

 healing process can advance so far as to cover the fracture. In 



this instance over thirty years 

 elapsed. The broken and 

 slivered end of the sapling offered 

 the most favorable lodgement 

 place for spores of fungi, and 

 for the accumulation of detritis 

 resulting from the constant 

 weathering of the exposed sur- 

 face. In these places moisture 

 is also conserved. The condi- 

 tions presented are favorable for 

 the germination of the spores 

 and entrance of the mycelial 

 threads. No more favorable 

 infection court could be pro- 

 vided whereby the fungus is 

 enabled to enter the heart wood. 



From this point of infection the mycelium spreads both ways 

 down the old trunk of the sapling, and upward in the branch 



71 . Polyporus igniarius, tongue 

 form of fruit body on beech. 



72. Polyporus igniarius. Hoof form on beech. 



which forms the newly established leader. The progress of the 

 fungus is comparatively slow, and the disorganization of the 

 wood accompanies it. The slow growth of the mycelium is 



