20 
Journal of Agricultural Research 
Vd. XXIV, No. I 
showed a lowering of the apparent optimum of from 3.5'' to 6^, Pho- 
nwpsis citri Fawcett, however, did not show similar changes. No such 
change in the optimum for growth of the species of Rhizopus studied 
by ^e writers was noted. It is possible that if the fungi had been grown 
for longer periods of time some such shifting of the optimum would have 
Fig. 13 .—Graph showing the increase of growth of Rhizopus artocarpi for consecutive 24’hour periods. 
become apparent. Hanzawa (p) found that the cardinal temperatures 
for some of these fungi were as follows: Delemar, nigricans, arrhizus, and 
nodosus have maximums of 42°, 35° to 37°, 42°, and 43° to 44°, respec¬ 
tively; oryzae, tritici, and chinensis all made a good growth at 38° to 42°; 
while the optimums for delemar, oryzae, and tritici were 30°, 30° to 40°, 
and 30° to 35®, respectively. Hagem (<?), on the other hand, found that 
