[Vor. 3 
56 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
range as compared with Verticillium albo-atrum which caused 
a trouble of almost identieal nature in the northern climates. 
Neither of these authors made controlled experiments to de- 
termine, if possible, exact ranges of temperatures. 
Humphrey (214), working in Washington with tomato blight 
caused by Fusarium orthoceras App. and Wollenw, and 
F. oxysporum Schlecht., found that the blight was favored 
by high temperatures. His statements were based on obser- 
vations made on experimental plots in 1911 and 1914 at Pull- 
man, Washington, coupled with the determination of the op- 
timum temperature for growth of the organism in the labora- 
tory at 86°F. or 30°C. This author suggested that the light 
intensity and wind are also factors in bringing about the 
typical symptoms of the disease. 
A preliminary report (Gilman, '14) of the relation of tem- 
perature to the occurrence of cabbage yellows was made at 
the Philadelphia meetings of the American Phytopathological 
Society in 1915. The full report of this work is as follows: 
Field observations.—On the experimental plot at Racine 
during the summer of 1912 it was observed that the attack of 
F. conglutinans occurred in the early part of July, when the 
plants had been set about two weeks. It was noted further 
that the plants which escaped or withstood the disease at this 
time remained healthy throughout the rest of the summer. 
Plants set out after this period were all practically immune. 
Upon looking up the temperature records of the summer it 
was found that the attack of the disease followed very closely 
a period of exceptionally hot weather. Table хуп gives a sum- 
mary of the observations made at three different times dur- 
ing the growing period. The strain numbers are those used 
by Jones and Gilman (715) in the development of a variety 
of cabbage resistant to yellows. Strains II, ІП, and VI were 
commercial varieties of Danish Ball-head imported from Den- 
mark; strains VII, VIII, IX, and X were from seed grown 
from resistant heads; strain XI was of the Flat Dutch variety 
imported from Germany; strain XII was commercial Houser; 
and strain XV, commercial Danish Ball-head. Further de- 
tails may be found in the publication mentioned above. The. 
