I go ANATOMY OF THE GYMNOSPERMS 



walls. The specific action in such cases is probably one of 

 hydrolysis, whereby the cellulose is resolved into soluble prod- 

 ucts of the general nature of glucose, and the results are pre- 

 cisely parallel with those produced by Mangin's maceration or 

 by strong sulphuric acid. But such changes should be studied 

 through the records of special cases. Tubeuf (72, 38-39) has 

 shown that Trametes pini acts in the first instance upon the 

 more highly lignified portions of the wall. The first effects of its 

 operations, therefore, are expressed in the solution and removal 

 of the primary wall, while the secondary and tertiary walls 

 remain behind as a skeleton, which may eventually become 

 corroded and disappear after prolonged action. 



Precisely the same action has been reported more recently by 

 von Schrenk as developed in the white rot of the red cedar 

 through the action of Polyporus juniperinus, von Schr. (69, 

 9-10). The holes produced in the trunk of the tree through 

 the action of this fungus often contain as much as three hun- 

 dred grams of the cellulose fiber. On the other hand, the same 

 author shows that in the red or brown rot of the same tree 

 numerous pockets are formed in the wood. These are occupied 

 by metamorphosed wood tissue which has cracked by shrinkage 

 so as to form small cubes adhering to the walls of the pockets. 

 An examination of such brown material shows it to be the resi- 

 due of the original structure after elimination of the cellulose, 

 the action involving a reduction of the cell wall by solution of 

 the less lignified parts, thus reducing the original structure 

 to the primary cell wall. Here again the action is seen to be 

 exactly contrary to that of the previous case, since, while in the 

 white rot the soluble substance, or hadromal of Czapek, is all 

 removed, leaving the cellulose behind, in the brown rot the cel- 

 lulose is removed, leaving behind a residue which von Schrenk 

 has been able to identify with the so-called hadromal. 



By the same authority identical changes have also been shown 

 to arise from the action of Polyporus versicolor in producing 

 the soft rot of Catalpa speciosa (68, 50-52). Tubeuf has also 

 directed attention to the fact that the same general changes may 



