360 BOTANICAL GAZETTE [NOVEMBER 
various poisons the toxic dose diminishes in amount with the elevation 
of the temperature of the body. MatTHews (8) found that a small 
rise in room temperature increased the toxic action of certain salts 
upon the eggs of the fish Fundulus heteroclitus, but no data in regard 
to the extent of the injury were reported. 
Considerable work has been done in recent years on the effect of 
toxic agents upon the germination and development of fungi, CLARK 
(g) determined the concentration of various chemical solutions neces- 
sary to produce injury, inhibition, and death in certain fungi. He 
found that a solution of n/4 HNO, killed the spores of Sterigmatocystis 
nigra within forty-eight hours, that n/8 to m/16 solutions of the same 
acid produced total inhibition of the spores, and that 7/32 gave great 
injury to the fungus. Botrytis vulgaris spores were killed by /16, 
and the plant was greatly injured by n/32 HNO,. With Penicillium 
glaucum, n/4 HNO, killed the spores, 2/8 and n/16 totally inhibited 
germination, and /32 gave decided injury. H,SO, gave similar 
results, but a concentration of n/2 was required to kill the spores of 
Sterigmatocystis and Penicillium. With CuSO,, 2/4 killed the spores 
of Sterigmatocystis, 2/8 to n/16 gave total inhibition, and 2/32 to n/64 
caused decided injury. Botrytis spores were killed by /16 CuSO,, 
inhibited by n/32, and the plant greatly injured by n/64. The 
spores of Penicillium were killed by 2” and inhibited by ” to 1/64, 
while decided injury resulted from 1/128. DuGGar (10) has reported 
upon special factors that influence the germination of fungous spores, 
and Miss Fercuson (11) has given some of the conditions for germi- 
nation in various basidiomycetous fungi. These recent papers have 
only an indirect bearing upon the work that follows, but have been 
very useful in the suggestion of methods for the solution of the 
problem, 
METHODS. 
The effect of the various toxic solutions at the different tempera 
tures was observed by means of the ordinary Van Tieghem cells. 
The manner of constructing and the method of using these have 
been fully described by CrarKk (g) and Duccar (10). 
These cells were never used a second time without being taken 
apart and thoroughly cleaned. In cleaning, the cells were boiled 
for twenty or thirty minutes, first in an alkali, then in an acid, and 
