Shade Tkek and Timbkr DiisiRoviNCr Fungi. 



2.1:7 



In all cases the fruit bodies of the fungus were formed at these 

 cut surfaces, there being no other place of exit. The tree was prob- 

 al)ly seriously wounded when young, and the mycelium entering 

 had spread all through the heart of the trunk and branches, but 

 was unable to form the fruit bodies until the larger limbs were 

 pruned. 



Several of the branches of this apple, bearing fruit bodies, were 

 taken for examination. Tlie character of the heart rot is in all 

 essential respects the same as that observed in the maple and beech. 



81. — Section of fruit body of Poly poms pinicola, shoicirig strata of tubes. 



POLYPORUS PiNICOLA. 



The pine destroying poljporus is widely distributed in the United 

 States and other north temperate regions. It occurs on various 

 conifers, on the pines, spruces, balsams, larches, etc. 



The fruit bodies are shelving, hard and firm, though not so hard 

 as those of Polyporus igniarius. They are perennial and, there- 

 fore, single specimens increase in size from year to year, Tisually 

 becoming broader below and of course thicker from each annual 

 accretion layer. 



The fruit body is marked on the upper surface by prominent con- 



