34 MISSOURI BOTANICAL GARDEN. 
lamella and the intercellular substance at the angles 
of the cells. If a similar section is treated with chlor- 
iodide of zinc the walls of sound wood cells are col- 
ored yellow-brown. ‘The cells from which the lignin ele- 
ments have been removed stain brown likewise. This 
indicates that they are not cellulose. In this respect the 
disintegration of the cypress wood differs from that caused 
in wood of the yellow pine by Trametes Pini. In the latter 
there is one form of disintegration in which the lignin ele- 
ments are gradually removed from the cell-wall, beginning 
with the secondary lamella, closely followed by the tertiary 
lamella. After this extraction a much thinner wall of pure 
cellulose remains. Some cases were found in wood of 
Pinus echinata, however, which could not be distinguished 
from pecky cypress, i. e., after the extraction of the lignin 
elements, as indicated by phloroglucin and hydrochloric 
acid, a membrane remains which is not cellulose. Hartig* 
describes a reaction much like the foregoing one in pine 
wood attacked by Merulius lachrymans, of which he says: 
‘¢ It appears as if there were a certain relation between the 
coniferin content of the cell-wall and the ease with which 
the wood is destroyed.’’ This test is so delicate that it 
shows the presence of a disturbing cause in the wood 
long before any evidence can be detected by the micro- 
scope. Other lignin reagents give similar results, although 
not so striking. Aniline sulfate turns sound wood brilliant 
yellow, while it leaves the affected lamellae almost color- 
less. Thallin and phenol give similar reactions. If the 
sections are treated with dilute KOH the normal wood 
cells are not affected beyond very slight swelling. The 
diseased cells swell more or less, particularly those parts 
which stained yellow with phloroglucin. After prolonged 
action of KOH, the delignified parts stain blue with chlor- 
iodide of zinc. This indicates that the first change in the 
* Hartig, R. Der ichte Hausschwamm 53. Berlin. 18865. 
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