220 



MANUAL OF TREE DISEASES 



yellow to light straw-yellow at the edge of the band. When 

 the bands have reached the cambium and bark, compact red- 

 brown felts of myceUum replace the destroyed tissues. In 

 tangential section the narrow bands show as yellow lens-shaped 

 areas with red centers. The radial bands of decay become 

 more numerous and finally coalesce, and in this way all the 

 heartwood and sapwood is decayed. 



The sporophores of the pathogene appear at various places 

 on the bark where the mycelium has penetrated the sapwood 



Fig. 35. — Upper svirface of fruitiDg-body of Fames rimosus. 



and bark. They are at first small, red-brown, hard knobs. 

 Each year a new layer of pores is added to the under surface. 

 After several years' growth large brackets or hoof-shaped bodies 

 are formed. The upper surface is dark brown or black and 

 much roughened by numerous fissiu"es which divide the surface 

 into irregular squares (Fig. 35). The under surface is dull 

 red-brown and extends upward over the edge of the sporophore 



