DISEASES OF TAXODIUM AND LIBOCEDRUS. 



cell-wall 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 



Ilartig, R. Zersetzungserscheinungen, etc. 35. 



13 



