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TEXT-BOOK OF FUNGI 



the ground, and superficially resemble a large toadstool 

 from above, but instead of gills, the under surface consists 



FIG. 115. Fames fomentari us, a large perennial fungus hav- 

 ing a hard, woody sporophore. The upper surface is sterile, 

 the hymenium being situated on the flattened under surface. 

 A new hymenial layer is formed each season upon the pre- 

 viously existing one. The different layers of hymenial tissue 

 are indicated by lines as shown in the section. Each layer 

 extends a little beyond the previous one, hence the hymenium 

 increases in area each year. The ridges on the surface 

 roughly correspond to the number of hymenial layers. One- 

 quarter nat. size. 



of closely packed tubes with the open ends pointing down- 

 wards. The entire mass of tubes separates quite readily 



