ENDOTHIA PARASITICA AND RELATED SPECIES. 47 
rate of growth might be due, at least partly, to more rapid drying of 
the agar at 31° C., or possibly to the more rapid development 
of some toxin, as was suggested by Balls (7) to explain a similar 
observation on the “soreshin” fungus. These observations threw 
doubt upon the accuracy of the writers’ previous conclusions, and 
made it seem possible that the optimum temperature of the species 
of Endothia might be well above room temperature. This could only 
be determined accurately by some method which would control tem- 
perature without altering the supply of moisture. Some months 
after the above tests were concluded it was discovered that the various 
species of Endothia would grow readily. on several liquid media. 
Consequently, several series of tests on liquid media were run parallel 
to those described above, except that the tests were continued for 
only four days. Experiment showed that at the higher temperatures 
the medium became considerably reduced by evaporation if left for 
a longer period. 
TESTS ON LIQUID MEDIA, 
In the series of tests on liquid media, all the species of which cul- 
tures had been obtained were grown on Cook’s medium (see p. 41) 
both in tubes and in flasks, using ten tubes and six flasks at each 
temperature. The cultures of Endothia gyrosa and EF. singularis 
were made with bits of mycelium from pure cultures. The other 
species were grown from conidia and the cultures were kept for two 
days at room temperature, in order to allow the conidia to germinate 
before being placed in the temperatures to be tested. 
The following temperatures were used for making the tests: 40°, 
37.5°, 35°, 29°, and 27°, and room temperature which was fairly 
constant at about 22°, 17°, 12°, 9°, 7°, 3°, and 2° C. There was some 
variation in the temperature of the incubators and refrigerators 
used, but in most cases they did not vary more than 1 degree above 
or below the temperature indicated. At 40° there were occasional 
traces of growth, especially in E'ndothia parasitica, but this may have 
occurred when the incubator dropped to 39° C. There is no regular 
and continued growth at this temperature. 
At 37.5° C. there was perceptible growth in all the species. This 
is in striking contrast to the results on solid media, as no species 
grew at a temperature above 35° C. on solid media. 
At 35° C. Endothia parasitica showed practically the same amount 
of growth as at 27° and 29° C. for the first three days, but fell behind 
after that. Z'. fluens showed less growth at 35° than at the lower 
temperatures. These two species were the only ones tested at 35° C. 
At 27° and 29° C. growth was markedly more abundant than at 
87.5°, and in most of the species was more abundant than at room 
temperature. In Endothia gyrosa and £. fluens mississippiensis the 
