Bull. 25, Div. Veg. Pnys. 6c Path., U S. Dept. of Agricu 



ture. 



Plate I. 



Fig. 1.— Sporophores of Polyporus schweinitzii Fr. 



Fig 2.— Polyporus volvatus Peck, growing from holes made in the bark 



BY DENDROCTONUS SP. 



