105 
one larva dead, softened, and blackened, but without appearance 
of fungous contamination. The pupa also dead and softening. 
August 13, no Sporotrichum apparent, only softened bodies of 
larva and pupa remaining. 
No. J6. July 31. An experiment parallel with the preceding, 
three cabbage worms being infected on the back. Eesults identi¬ 
cal with those of No. 15, one worm pupating August 2. Both 
larvae and pupa died, blackening and becoming deliquescent, with¬ 
out appearance of muscardine. The pupating larva proved to 
have been parasitized, as is noted August 7. 
These two experiments with infection material derived from acid 
cultures throw some doubt on the effectiveness of that kind of 
material, but as the larvae evidently died from the common bac¬ 
terial disease of the cabbage worm, it is possible that the previ¬ 
ous presence of this disease prevented the development of the 
fungus—an hypothesis that is made more probable by the fact 
that spores of Sporotrichum will not germinate on decaying media. 
No. 17. July 28. An infection experiment upon the larva of a 
butterfly (Grapta interrogations) taken from the elm. This cat¬ 
erpillar was infected with spores from agar culture No. 11, itself’ 
derived, as will be remembered, from agar culture No. 1, derived 
in turn from the dead larva with which this series began. The 
material here used was consequently at two removes from the 
dead insect. .. The spores were placed along the center of the back 
of the caterpillar at 10:30 a. m., the infected insect being then shut 
up in a large covered glass dish, with a layer of moist sand on the 
bottom, upon which leaves of elm were scattered as food. At 9 
a. m., July 30, this larva had pupated, of course casting off the 
skin upon which the spores had been placed. It was examined 
daily without note of change until August 7. The pupa at this 
date was still alive and apparently healthy, but exhibited a slight 
growth of Sporotrichum from a point about the size of a pin-head 
on the ventral surface, at the edge of the pupal wing-pads. This 
ventral point was in immediate contact with the cast skin still 
bearing the fungus spores. August 13 this pupa was dead, with 
a slight external growth of Sporotrichum g lobuliferum—at that 
time in fruit. 
No. 18. July 28, 10:00 a. m. An infection experiment similar 
to the preceding, except that a cabbage worm (Pieris rapce ) was 
used instead of the Grrapta larva, and that a cabbage leaf was 
placed in the dish instead of leaves of the elm. The caterpillar 
was_ touched with spores from No. 11 on the back, immediately 
behind the head. July 30 the fungus was growing freely from the 
point of infection and spreading to the sides of the body. July 
31 it had enveloped the body near the head, and had also ex¬ 
tended on the ventral surface the entire length of the caterpillar. 
l arva had in the meantime changed to that of 
mushed raspberries wherever the fungus was growing, and August 
1 the entiie cabbage worm was of the same crushed-raspberry 
color. August 2 the Sporotrichum had spread all over the sur¬ 
face, and August 7 it was well developed everywhere and covered 
with ripe spores. 
