166 The Philippine Journal of Science 1915 
at the cut surface. They were then touched with the sterile loop 
and transferred to an agar slope. Abundant growth practically 
never failed in the test tube when microscopical examination 
had previously shown the presence of bacteria in the body cavity. 
CONTROLS 
During the exaltation series, controls of uninoculated insects 
were kept; and besides, some insects were inoculated with broth 
alone. Such controls remained in good condition for days with 
but little diminished numbers. In addition to the above, controls 
were made of insects inoculated with other bacteria. Bacillus 
prodigiosus was carried through 12 insects transfers at the 
same time as 12x of Coccobacillus acridiorum. The death of 
the insects followed the inoculation with about the same regular- 
ity and after as short an interval as in the case of Coccobacillus. 
Cultures were made from the insects after many passages and 
sprayed on the food of locusts in corrals and in the field. Several 
insects found dead in the corrals showed Bacillus prodigiosus 
apparently in pure culture in the body cavity. Precautions 
were taken to avoid surface and gut contamination in making 
cultures. One insect found dead in the field after spraying with 
Bacillus prodigiosus also showed this organism in the body cavity. 
Another control series was started with inoculations of the 
gut contents of an insect which died at a station some distance 
from the laboratory where inoculation experiments were being 
carried on. At this station there was no possibility of accidental 
infection with Coccobacillus acridiorum from the laboratory. 
Insects died just as promptly after similar intraabdominal doses 
of this material as after doses of the Coccobacillus, and ingestion 
experiments in cages gave, if anything, better results (Tables 
III and V “Singalong’”’). Field experiments were alike negative 
with both strains. 
A special experiment was arranged to compare the effect of 
small doses of the original culture of Coccobacillus acridiorum, 
as received, with those of a culture of the same source which 
had been passed through a series of locusts (“12x” series). 
The exalted culture had been passed through 12 series of locusts, 
with one or two exceptions in the nymph stage. It was kept 
at refrigerator temperature for about three weeks, with the 
exception of about three days at room temperature. This cul- 
ture came directly from the leg of an infected insect. It was 
then planted on agar to get a fresh growth and inoculated into a 
set of mature locusts. From the first one dying, a new set 
