ILLUSTRATIONS. 



PLATES. 



Page 

 Plate I. Fig. 1. — S-porophoreB oi Folyporus schweinitziiFr . Fig. 2. — Polyporus 

 volvatus Peck, growing from holes made in the bark by Dendrocio- 



nus sp 56 



II. Log of Balsam Fir showing decay caused by Polyporus schweinitzii Fr. 56 



III. Log of White Spruce showing early stage of decay caused by Poly- 



porus pinicola (S wartz ) Fr 56 



IV. Log of White Spruce showing advanced stage of decay caused by 



Polyporus pinicola (Swartz) Fr 56 



V. Sporophores of Polyporus pinicola (Swartz) Fr 56 



VI. Fig. 1. — Red Spruce: Early stage of the decay caused by Trameies 

 pini forma abietis. Fig. 2. — Red Spruce: Advanced stage of the 



decay caused by Trametes phii forma abietis 56 



VII. Log of Balsam Fir showing decay caused by Trametes pini forma 



abietis 56 



VIII. Fig. 1 early and fig. 2 late stage of decay of Larch caused by Trametes 



pini forma abietis 56 



IX. Polyporus subacidus Pk., Polyporus pinicola (Swartz) Fr., and Trametes 



pini (Brot. ) Fr. forma abietis Karst 56 



X. Work of Poly poms pinicola (Swartz) Fr. and Trametes pini (Brot.) Fr. 



forma abietis Karst 56 



XL Stages of decay induced in Spruce by Polyporus subacidus Pk. and 



Polyporus sulfureus {BuU. ) Fr 56 



XII. Various forms of sporophores of Trametes pini (Brot.) Fr. forma 



abietis Karst 56 



XIII. Block of White Spruce wood showing injury caused by Polyporus 



sulfureus 56 



XIV. Fig. 1 early stage and figs. 2 and 3 successively later stages of the 



decay caused in White Spruce by Polyporus subacidus Peck 56 



XV. Fig. 1. — Cross section of log of Spruce showing decay caused by Poly- 

 porus subacidus Peck. Fig. 2. — Resupinate form of sporophore of 

 Polyporus subacidus Peck on Spruce log 56 



TEXT FIGURES. 



Fig. I. Polyporus schweinitzii Fr. growing on a fallen Fir 21 



2. Cross section of Spruce wood showing masses of mycelium of Polyporus 



pinicola (Swartz ) Fr 28 



3. Base of Spruce branch, showing its resistance to the attack of the 



mycelium of Polyponis subacidus Pk 47 



7 



