[Vor. 7 
72 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
of wood illustrate the water-proofing effect of resin on the wood, 
especially above 50 per cent humidity. It is believed that 
resin cannot be relied upon as an indication of the durability of 
lumber although present in amounts as high as 12-15 per cent, 
for it is seldom equally distributed in the wood. The regions of 
low resin content are sources of weakness if wood-destroying 
fungi gain access to them under favorable moisture conditions. 
(4) The germination of the spores of Lenzites saepiaria on 
wood shavings was accomplished at various relative humidities 
ranging from 63 to 100 per cent. "The germination curve illus- 
trates the fact that spore germination is exceedingly accelerated 
when the atmospheric humidity is high enough to maintain fibre 
saturation of the wood. 
(5) A humidor for maintaining constant humidity and temper- 
ature is described. It is provided with (1) a dew-point appa- 
ratus for the determination of humidity, and (2) a weighing 
device so that the samples can be weighed without opening the 
humidity chamber. 
The writer wishes to express his appreciation of the financial 
aid accorded him by the Southern Pine Association, without 
which this work would have been impossible. Thanks are also 
due the staff of the Missouri Botanical Garden for coóperation 
and for facilities for the work, and to Dr. Hermann von Schrenk 
for helpful suggestions. 
LITERATURE CITED 
Dixon, H. H. (98). On the effects of stimulative and anaesthetic gases o paid 
tion. Trinity College Botanical School, Notes 1898: 97-105. f. 1 
Falck, R. (09). Die Lenzites-fáule des Coniferholzes. Móller's ul 
schungen. Heft 3: 1-234. pl. 1-7. f.24. Jena, 1909 
Fowle, F. E. (10). Smithsonian physical tables. Smithsonian Misc. Coll. 58!: 1- 
318. 1910. (See tables 135 (d) and 136. 
pra . (60). Untersuchungen über die Keimung der Pilzsporen. Jahrb. f. 
ss. Bot. 2: 267-337. pl. 26-35. 1860. 
Pent E. (09). Untersuchungen über Immunität und Krankheitsempfünglicht- 
keit der Holzpflanzen. Naturwiss. Zeitschr. f. Forst u. Landw. 7: 54-75, 87- 
114, 129-160. f. 1-5. 1909. 
Newlin, J. A., and Wilson, T. R. C. (19). The relation of the shrinkage and strength 
properties of wood to its specific gravity. U. S. Dept. Agr. Bul. 676: 1-35. 
f. 1919. 
