EFFECT OF KILN DRYING, ETC., ON FUNGI IN WOOD. 38 
ment of heating a mill, the timbers of which were infected with dry 
rot, to about 115° F. The heat was applied from Saturday noon 
until Monday morning on fcur different occasions. Hoxie states that 
specimens were cultivated from 40 of the badly rotted beams and only 
4 showed living fungi. The fungus in this case was given as Meru- 
lius lachrymans, which is particularly sensitive to heat. Snell, using 
#-inch blocks of spruce artificially inoculated with Lenzites sepiaria, 
Lenzites trabea, Trametes serialis, Lentinus lepideus, and Trametes 
carnea, respectively, subjected these blocks to both moist and dry 
heat at varying temperatures and periods of time. The results of 
his tests indicate that moist heat is much more effective in killing the 
fungi than dry heat. None of the fungi within these blocks were 
able to withstand 131° F. for 12 hours at moist heat, while it took 
a heat of 221° F. for 12 hours to kill all the fungi with dry heat. 
The experimental data are limited to tests on #-inch blocks, but 
statements are made that the temperatures employed in the kiln 
drying of lumber and in the various wood-preservation processes are 
sufficient to kill any fungi within the wood. 
MATERIAL USED IN THIS STUDY. 
The first lot of material consisted of 18 pulp logs of northern 
white spruce (Picea canadensis)* shipped in from northern Wiscon- 
sin. Six wood-destroying fungi were found infecting this material. 
In some cases the rots of two fungi were present in the same log; as, 
for example, Polyporus anceps in the sapwood and 7'rametes carnea 
in the heartwood, a faint colored zone showing at the junction of the 
two kinds of rot. 
The second lot consisted of a carload of mixed hardwood and 
conifer logs 16 feet long shipped in from the Menominee Indian 
Mills, Neopit, Wis. These logs were selected by the writer from 
standing green trees on the logging area. An attempt was made to 
find trees with fruiting bodies of the attacking fungus attached, but 
this was not possible in all cases. A total of 23 logs representing 9 
hosts and several wood-destroying fungi comprised the shipment, a 
detailed list of which is given on a succeeding page. The blue-stain 
fungus (Ceratostomella sp.) was found in three of the hosts and 
Torula ligniperda in two hosts. Dark brownish and black discolor- 
ations extending the full length of the log were found bordering the 
incipient decay of the brown cubical rot of tree No. 3 (eastern white 
pine) and trees Nos. 8 and 9 (eastern hemlock). Upon examining 
sections of the dark-colored wood under the microscope, typical spore 
chains of 7. ligniperda were observed within the wood cells. The 
association of this stain-producing fungus with typical wood- 
destroying fungi in decaying wood is apparently quite general (6). 
At the laboratory sawmill, disks 3 inches thick were cut from the 
middle point of each log. ‘These disks were numbered and the decay 
area sketched upon record cards. Photographs taken of some of 
these disks show the types of infection. (PI. I.) 
There-was some doubt as to the identity of the fungus causing the 
rot in tree No. 18, basswood (Ztlia americana). The butt log 
showed a slight hollowing at the base, and within this hollow there 
+ Authorities for the scientific names are given in the list on page 4. 
