30 
the infection material for one experiment was obtained from the 
hibernating beetles (Disonycha) already mentioned; that for seven 
others came from chinch-bugs dead with muscardine; that for 
one from a dead cabbage worm; and that for the remaining 
nine from various cultures of Sporotrichum. The infection mate¬ 
rial for the experiments with other insects was all from the culti¬ 
vated fungus. 
Cultures of Sporotrichum. 
Sterilized Cultures .—The culture apparatus used by us was in 
all cases either the common test-tube with a cotton plug, or a 
glass fruit jar of the Mason pattern (usually of a capacity of 
two quarts), the metal cap of which screws on to the top of the 
jar with a fiat rubber ring intervening. The caps were altered by 
closely soldering a tin tube into an opening in the top of each 
(see Plate V., Fig. 1), as a safeguard against accidental infection 
by bacteria when the spores were sown upon the medium, and 
also for the purpose of convenient plugging with cotton as a sub¬ 
sequent protection. 
In charging this jar with the culture medium, the metal cap 
was removed and the jar was partly filled with the corn-meal 
batter, mixed barely thick enough to settle smoothly, and was 
then placed upon its side, so that the mixture collecting at the 
lower part of the jar might present as large a surface as possible 
for the growth of the fungus. This culture jar worked very satis¬ 
factorily, any secondary infection of the culture rarely interfering 
with the growth and complete development of the Sporotrichum. 
The cover of the jar was of course removed to get access to its 
contents, and if it was desired to preserve the culture for some 
time without deterioration the jars were left open until the con¬ 
tents were dried out. (See Plate VI.) It was found that such 
dried masses of corn meal with surfaces covered with Sporotrichum 
growths could be readily and successfully freshened and revived 
after some months by simply moistening the mass. 
Our test-tube cultures on agar-agar, the spores for which were 
derived from the tube of this fungus sent us by Prof. Thaxter, 
were all made in the botanical laboratory of the University of 
Illinois. They served merely to demonstrate the readiness and 
convenience with which cultures of this fungus may be made on 
peptonized agar, the substance most commonly used for the cul¬ 
ture of bacteria on solid media. 
A much larger number of cultures on other substances were 
made in my awn laboratory, mostly by Mr. John Marten, one of 
my entomological assistants. As it was our principal object at 
this time merely to ascertain what medium could be used most con¬ 
veniently and successfully for the multiplication of this fungus 
on a considerable scale, for experimental purposes, the details of 
our cultures were not followed out beyond the point of immediate 
practical utilization. For this reason scarcely any experiments 
were undertaken under conditions other than those present in an 
ordinary occupied room, and only such notes of the progress of 
