so 18y Roberg: Bacterial Infections 333 
The washed fiy was placed in Dunham’s peptone and crushed. 
This was incubated for twenty-four hours and reinoculated into 
three successive changes of Dunham’s peptone for enrichment 
and plated on Dieudonné’s medium. The plate did not reveal 
the presence of cholera vibrios. 
c. When twenty-six hours had elapsed after the vibrio feeding, 
the second fly was secured and washed in Dunham’s peptone. 
This was incubated twenty-four hours, enriched in peptone three 
times, and inoculated on Dieudonné’s medium. The plate when 
examined did not reveal the presence of cholera vibrios. 
The washed fly was placed in Dunham’s peptone, crushed, 
incubated, enriched three times in peptone, and inoculated on 
Dieudonné’s medium. The plate showed pure cultures of cholera 
vibrios. 
d. When thirty-four hours had elapsed since the vibrio feed- 
ing, the third fly was taken and subjected to the processes re- 
corded in 6 and c. Cholera vibrios could neither be found in 
the surface washing nor in the crushed fly. 
e. A number of flies were taken- from the stock jar and 
allowed to feed upon an agar-slant culture of cholera vibrios. 
After being fed, they were placed in a flask. When twenty-two 
hours had elapsed since they were fed on vibrios, three of them 
were secured and placed in Dunham’s peptone to wash off the 
surface bacteria. This was incubated for twenty-four hours 
and then enriched three times in peptone and plated on Dieu- 
donné’s medium. The examined plate showed no cholera vibrios. 
The washed flies were crushed in Dunham’s peptone, incubated 
for twenty-four hours, enriched three times in peptone, and 
plated on Dieudonné’s medium. Examination of the plate 
showed pure cultures of cholera vibrios. 
CONCLUSIONS FROM RESULTS 
Aphiocheta ferruginea, when fed on media infected with 
cholera vibrios, harbors the organisms on its body for ten hours 
and in its intestinal tract for twenty-six hours. 
Failure to isolate cholera vibrios from the crushed fly in 6, 
in which ten hours had elapsed since it was fed on cholera 
vibrios, was no doubt due to a killing of the organisms by using 
a too hot platinum needle in making inoculation transfers. 
SUMMARY AND CONCLUSIONS 
Aphiochzxta. ferruginea is a species of fly which breeds in 
human feces, and as indicated by indoor laboratory experi- 
