DISEASES OF TAXODIUM AND LIBOCEDRUS. 41 
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 HCl, 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. Atthe 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 
19 
