12 
BULLETIX 1053, F. S. DEPARTMENT OE AGRICULTURE. 
The longest periods during which any spores of the species 
studied have given germination are shown in Table 2. 
Table 2. — Maximum period of retention of viability of the oa s id ios pores of 
Lenzites sepiaria, Lenzites trabea, Trametes serialis. Fomes roseus, and 
Lentinus lepideus. 
Species and source of sporo- 
phores. 
Period, of retention of viability. 
Dates. 
Spores germinated 
after — 
Germination. 
Lenzites sepiaria: 
Madison. Wis., Xovem- Anr. 13, 191S.toFeb. 10, 1921. 2 years 10 months a.... 25 per cent, 
ber, 1917. 
L. trabea: 
Cotton mill, Centerville, February, 1920, to February, 1 year a 60 per cent. 
R. I., February, 1920. 1921. 
Trametes serialis: 
Madison, Wis., Xovem- November, 1916. to Febru- 4 years 3 months a 2percent. 
ber, 1916. ary, 1921. 
Fomes roseus: 
Wisconsin, June, 1917, June, 1917, to December, IS months t> Few in thousands. 
on tamarack I Larix). 1918. 
Minnesota, June, 1919, on June, 1919, to Feb. 10, 1921... 1 years months a Less than 1 per 
Prunus. cent. 
Lentinus lenideus: 
Cotton mill. Xew Bed- July 5, 191S, to Feb. 10, 1921.. 2 years 7 months b Do. 
ford, Mass., July 5, 191S. 
« These figures refer to the last tests; further tests may show that these spores survived 1 onger periods. 
6 These spores gave no germination in 20 months. 
VIABILITY OF BASIDIOSPORES DELED AT DIFFERENT TEMPERATURES. 
Because of the lack of sufficient quantities of basidiospores, tests 
upon the effect of drying are neither complete nor entirely satisfac- 
tory, because only one series has been conducted. It is to be expected 
that the age of the spores will make some difference in their resistance 
to drying and that, as pointed out previously, individual casts of 
spores may vary, hence the tests here reported are only indicative. 
For example, it will be noted (Table 3) that spores of Trametes 
si rialis '2 years old succumbed sooner at 2S : C. (82 c F.) than at 32 c 
C. (89° F.). 
At 2S C and 32 c C. the spores of Trametes serialis and Lentinus 
lepideus of the ages given ceased to germinate after an exposure of 
about 10 weeks to dry incubator conditions. At 36' C. (97° F.) it 
took about a month to kill all or most of the spores. 
At 40 c C. (104:° F.) it will be noted (Table -±) that in one week 
there was a decided drop in the percentage of germination of the 
spores of the three species tested. Those of Fames roseus did not 
survive one week at 40° C. In two months, however, the spores of 
Lenzites sepiaria were not all killed, nor those of Trametes serialis 
in six weeks. These -pores were fresh, while those in the tests at 
36 z C. were not absolutely fresh. 
