[VoL. 3 
486 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
this stain. In radial sections it may be noticed that this 
maroon discoloration starts from the bordered pits, especially 
if they are perforated with fungous hyphae. The hyphae seek 
the bordered pits, these apparently serving as the only places 
where the hyphae pass from one lumen to another. 
In the tangential section the discoloration in the earliest 
stages occurs only in the neighborhood of the medullary rays. 
While this discoloration is taking place the tertiary lamella 
first contracts and then practically disappears. The second- 
ary lamella likewise shrinks as it takes on this brownish red 
color. This must be due to the gradual hydrolysis of cellu- 
lose and probably the simultaneous hydrolysis of coniferin 
through the action of emulsin. The secondary lamella shrinks, 
but in the last stages of decay there are still brown, fragile 
remains of this layer, together, undoubtedly, with infiltrated 
by-products from the decayed middle and tertiary lamellae. 
The middle lamella seems to disappear almost simultaneously 
with the decay of the secondary. 
With chloriodid of zine the decayed wood gives the same 
test as in the sound wood, a brown color. This is true in all 
stages of decay. There is no indication of free cellulose at 
any time during decay. Partially delignified sections, cut 
from the same surface as the sections on which the above 
lignin tests were made, were treated with a 5 per cent potas- 
sium hydroxide for some time. On the addition of chloriodid 
of zinc the lamellae yielded a purplish blue reaction, where 
only partially delignified by the fungus; but where decay was 
complete a brown color was obtained. These results show that 
the first step is the splitting of lignin, and simultaneously 
with this there is a complete hydrolysis of the cellulose as 
fast as it is set free. Undoubtedly some of the substances 
giving the lignin reaction are also used up. 
Other lignin tests gave similar results. The action of ani- 
line sulphate was marked. The sound wood was colored yel- 
low, and as the diseased region was approached the color be- 
came browner, although the yellow element did not seem 
to be lost entirely. Indications are that in the decayed wood 
some of the substance that gave the lignin reaction still 
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