DISEASES OF TAXODIUM AND LIBOCEDRUS. 35 
cell-wail is the removal of some of the incrusting sub- 
stances, probably coniferin and vanillin. The KOH re- 
moves the remaining substances and leaves the cellulose 
membrane free to react with chloriodide of zinc. Very 
much rotted wood stains intensely blue after treatment with 
KOH. The blue color appears first about the pits, and 
diffuses towards all sides, looking much like an inkspot on 
which water has been dropped, causing it to diffuse irregu- 
larly over the surrounding area. Sound wood stains yellow- 
brown with chloriodide of zinc, even after treatment with 
KOH. With iodine and sulphuric acid, rotted wood stains 
brown. 
A very different form of disintegration now and then 
occurs (Pl. 4, fig. 3). What the reason is why one form 
occurs at one time and a second at some other ‘time, I can- 
not explain. Large holes appear in the sound wood, filled 
with a spongy mass of white fibers. The holes have a 
white or tawny lining of fibers, which can be pulled off in 
groups. These holes are as large as the ones filled with 
brown powder. The change in the wood cells is almost 
exactly like that found in pine wood attacked by Trametes 
Pini,* above described. The secondary lamella is gradually 
changed so that it stains purple with chloriodide of 
zinc, that is, the lignin substances have been entirely 
removed. Very soon after the first signs of delignification 
become evident, the primary lamella separates into two 
lamellae, which are then dissolved. This causes the indi- 
vidual wood cells, or rather the cellulose fibers, to fall 
apart. No intermediate steps between the lignified cell- 
wall and the cellulose wall are to be detected, which gives 
the impression that the extraction of the lignin elements 
must take place all at once. The amount of pure cellulose 
fiber thus found in one hole is surprising. From a hole 
3-4 inches long several grams were obtained of many white 
* Hartig, R. Zersetzungserscheinungen, etc. 35. 
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