^ Vd 



Bui. 25, Div. Veg. Phys. & Path., U. S. Dept. of Agriculture. 



PLATE XV 



Ly^ 



\^m 





Fig. 1. Cross section of log of Spruce showing decay caused by 



POLYPORUS SUBACIOU'^. PeCK. 







Fig. 2. Resopinate form of sporophore of Polyporus subacidus Pec - 



