DISEASES OF TAXODIUM AND LIBOCEDKUS. 



small bodies which he finds he describes as " rounded in 

 form." He suggests that they may be crystalline, and 

 that the deposition of the lime in the walls is made in the 

 form of crystals. "If this be true it may be asked 

 whether the action of the cell-wall when viewed with polar- 

 ized light may not be explained by the refraction of these 

 bodies." Hartig, however, did not prove the crystalline 

 nature of the bodies. The small bodies from the humus 

 compound dissolve in HC1, which might indicate them to 

 be crystals of calcium oxalate. They are evidently massed 

 together in the humus compound, and become visible only 

 when the latter is removed. It is not at all improbable 

 that they were constituents of the cell-wall, which were not 

 destroyed by the disintegrating factor and remained un- 

 harmed, imbedded in the liquid mass of humus compound. 

 The present data do not warrant any definite conclusions 

 as to their real nature and origin. 



From the description just given of the formation of the 

 humus compound, and comparing this with the normal 

 method of disintegration of the wood, it seems that the 

 process may be summed up as follows : For some reason, 

 the normal lignified membrane changes, i. e., certain of its 

 constituents, which ordinarily react with phloroglucin, are 

 extracted. Then more profound changes take place ending 

 in the formation of a humus compound. This ordinarily 

 diffuses through the adjoining cells, and ultimately hardens 

 in the tracheids surrounding the rotted area and in the medul- 

 lary rays . At the same time all contents of the cells, hyphae, 

 starch grains, etc. , are covered. Numerous experiments were 

 made to determine the approximate per cent, of matter solu- 

 ble in dilute KOH, both in much rotted wood and in wood 

 immediately surrounding the holes, apparently sound. The 

 amounts were found to vary between wide limits. On an 

 average about 34% was obtained from much rotted wood, 

 the remaining 66% consisting of pieces of wood fibres 

 not transformed. In the wood immediately surrounding 



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