74 MISSOURI BOTANICAL GARDEN. 
found in a number of cases. How common this is cannot 
be said, as the number of specimens examined was from 
but a small number of trees. The threads have marked 
attachment organs (Pl. 5, fig. 9 ‘*d-f’’) which have 
been described under the cypress disease. 
In the rotted wood, and particularly around the same, the 
cells are often filled with great masses of spores like those 
seen in isolated cases in the cypress (Pl. 5, fig. 2). These 
spores are present in such numbers, that they often com- 
pletely fill the tracheids. Several spores were found with 
very fine hyphae attached (fig. 5) and many showed small 
knobs at one end. It will be necessary to see a large num- 
ber of trees to determine where these spores came from. 
LOCALIZATION. 
The localization of the diseased areas is quite as marked 
in Libocedrus as it is in Taxodium. One may have a 
block of wood 3X3X1 in. which looks perfectly sound, but 
when split longitudinally it may contain a sharply defined 
lenticular hole. It is suggested that probably similar 
reasons to those given for the cypress hold here. The 
investigation with respect to this point is to be regarded as 
but begun. When it becomes possible to grow the fungus 
found in the holes one may expect to reach more decisive 
conclusions. 
SUMMARY. 
In the foregoing, two forms of decay have been de- 
scribed, one destroying wood of Taxodium distichum, the 
other of Libocedrus decurrens. In both cases the wood 
is destroyed in localized areas, which are surrounded by 
apparently sound wood. The cell-walls are changed into 
compounds which diffuse through the walls and fill the cells 
surrounding the decayed center; and these have been called 
humus compounds. In both, a fungus mycelium occurs 
with strongly marked characteristics, which flourishes 
52 
JL 
