20G 
Mycologia 
The test blocks were oven-dried at lOO to 105° C. for 20 hours 
and weighed. To moisten again they were placed in a dish of 
tap water, brought to a boil, and allowed to cool. 
The tube cultures were prepared by placing a layer of wet 
sterilized sphagnum moss in the bottom, followed by a layer of 
moist sterile sand up to about two-fifths the length of the tube. 
The test block was embedded in this sand for about one-half 
its length and surrounded by culture blocks of spruce or beech, 
the former being used in the case of fungi known to inhabit 
coniferous timber and the latter in the case of hardwood fungi. 
Over the whole was packed a layer of wet sphagnum. Tap 
water was then added to saturate the sphagnum and sand in 
the bottom and the tubes were then tightly plugged with ab- 
sorbent cotton. 
After sterilization of about i hour at 12 pounds steam pres- 
sure, the tubes were allowed to cool and were inoculated on 
August 28 and 29 with various wood-destroying fungi, among 
which are included many of the most active ones prevalent in 
the United States. 
With the exception of MeniUus lachrymans, which was placed 
in the incubator at 22 to 26° C., all the cultures were held at 
laboratory temperature, which varied considerably with the 
seasons. After one year the tubes were opened and the blocks 
examined. Plate 162, figs, i and 3, illustrate the method of 
test and the luxuriant mycelial development which was attained 
by the end of the test period. 
Upon removal, the test blocks were oven-dried and re-weighed. 
Tables I and II present the essential data and results. 
An examination of Table I shows that the heartwood of green- 
heart proved highly resistant, and in most cases practically im- 
mune, to all the fungi used, in spite of the fact that the organisms 
developed luxuriantly in the tubes. Very little effect on the 
wood was noted in a visual examination. Losses in weight under 
0.5 per cent, are not recorded, as this may lie within the experi- 
mental error. 
Table II shows a somewhat different state of affairs, for the 
