[ VoL. 5 
48 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
This experiment was repeated with soil from the ехреті- 
mental field at Racine. The soil was sifted through а 40- 
mesh sieve and in this earth cabbage was then planted. All 
the plants were found diseased at the end of fourteen days, 
while the plants in a control pot of uninfected soil remained 
healthy. Plants in a pot of infected soil, unsieved, showed 
the disease slightly earlier, at the end of twelve days, this 
difference in time being due probably to the fact that in the 
sieved soil the organism existed only as spores and, there- 
fore, took longer to infect than where it grew rapidly from 
mycelium in the old host tissue. 
TEMPERATURE 
Literature.—Before discussing the significance of the tem- 
perature relation in the case of the attack of F. conglutinans 
on cabbage, the results obtained in other diseases where tem- 
perature has proven of pathological importance should be con- 
sidered briefly for comparison. 
Upon making a careful review of the literature it was 
found that our knowledge of this field is very limited and 
fragmentary, although the importance of temperature is gen- 
erally recognized. Earle (’02), in a paper on the environ- 
mental factors concerned with disease, discussed the tempera- 
ture relations in a general way, pointing out that for health, 
the plant must have temperatures of the proper degree for 
growth. Duggar (709) also recognized the importance of 
temperature in relation to the susceptibility of the host to 
fungous attack, but in a paper of this nature he could make 
nothing more than a general statement. Reed (710) ша sim- 
ilar paper paid more attention to this one of the many envi- 
ronmental factors involved, and showed that the temperature 
most favorable for the attack of a fungus is dependent en- 
tirely on the particular organism under consideration. He 
cited as examples of this relation the bitter rot of apple which 
is favored by high temperatures and the leaf curl of the peach 
which thrives best under cool weather conditions. Klebahn 
(719, p. 88) stated that, although the temperature is undoubt- 
