Brown: Timber Rot 
19 
Fig. s- Cross section of small chestnut log showing white areas charac- 
teristic of one stage of decay. X 8/9. 
Fig. 6. Portion of the same enlarged; cavities in process of formation. 
Fig. 7. Appearance of tissue in the peripheral type of decay ; the hyphae 
are closely appressed to the cell walls and all the cells are undergoing dis- 
integration. 
Fig. 8. Germinating spores in hanging drop culture ; note vacuolation in 
the germ tubes. 
Plate CL 
Fig. 9. Cross section of smalt chestnut log showing final stage of decay. 
X 3. The contents of the pockets have entirely disappeared. 
Fig. 10. Tangential view of pockets. X §. The white cellulose contents 
have not been dissolved. 
Fig. II. Tissue at the edge of a diseased area. Note (a) the delignifi- 
cation of the elements, (h) the separation due to the disappearance of the 
middle lamella, and (c) final digestion. 
Fig. 12. Cross section of chestnut wood showing scattered, irregular-shaped 
areas where disintegration has occurred. The wood between the pockets is 
still sound. 
Fig. 13. Tangential section of oak wood showing shape of the pockets in 
side view. 
Fig. 14. Cross section of chestnut wood showing a portion of diseased 
tissue which includes one vessel. 
Fig. 15. Same as figure 13. Note the partially digested, thick-walled 
prosenchymatous elements projecting into the cavity. 
Fig. 16. Cross section of oak wood; diseased area on the extreme right 
(the hazy appearance in the center of the figure is not due to the attacks of 
the fungus). 
Plate CLI 
Figures 17-20 are photographs of pen drawings. 
Fig. 17. Spores, germination, and germ tubes forty-eight hours after 
germination. 
Fig. 18. Cross section of a fruit body ; hymenium above. 
Fig. 19. Portion of hymenium enlarged showing cystidia, basidia and 
spores, and immature basidia. 
Fig. 20. Cross section of chestnut wood at margin of diseased area, show- 
ing sound cells at a, partly delignified cell at b, and partly digested cells at c. 
Fig. 21. Young fruit bodies coalescing to form extensive hymenial surfaces. 
Fig. 22. Cross section of chestnut wood at margin of a pocket. The shad- 
ing indicates the extent of delignification in the cell walls. 
Fig. 23. Wood parenchyma cells of chestnut in longitudinal view; hyphae 
extending horizontally through the pits. 
Fig. 24. Mycelial strand extending through the tissue. These serve to con- 
nect the pockets which are subsequently formed. 
Fig. 25. Pith ray and neighboring parenchyma cells in tangential view. 
Hyphae have passed through the pits, eroded the cell wall, and then disap- 
peared, leaving irregular openings. 
