KiB yb Roberg: Bacterial Infections 329 
Summary of results—Specimens of Aphiocheta ferruginea 
readily pass through a wire screen having 16 squares to the 
linear inch. It is possible for them to pass through 8 layers 
of tightly stretched gauze having 20 squares to the linear inch. 
The time elapsed from the laying of the eggs to the emergence 
of the adult is from nine to ten days. Eggs are laid by the 
flies five days after emergence. Pupation of the larve takes 
place five or six days after they are hatched. 
By indoor-breeding experiments Aphiocheta ferruginea are 
indicated as the commonest of the small flies which breed in 
feeces. 
SERIES II 
To ascertain whether larvee when growing in a medium in- 
fected with cholera vibrios contain these organisms in their 
intestinal tracts, the following experiments were performed: 
a. On April 1 eggs were removed from the beaker trap 
(series I) and placed on a cholera culture growing on a Petri 
plate of Dieudonné’s medium. This plate was placed in a large 
glass-covered stender dish to await the hatching of the larve. 
b. On the same day a similar plate culture of cholera was 
placed in a large gauze-covered stender dish containing fzeces 
to attract flies, which in turn would deposit their eggs upon the 
medium. As soon as the dish was exposed, a small fly was seen 
to enter through the gauze and immediately leave the dish again. 
As it was possible for the flies to leave the dish after entering 
it and disseminate infection, this method of securing eggs was 
abolished. 
The eggs placed on Dieudonné’s medium in a hatched out 
in twenty-four hours. The larvee lived for twenty-four hours 
and then died from a lack of nourishment. 
c. On April 2 three larve were secured from the bottle of 
feeces-agar mixture (series I) and placed on the surface of a 
cholera growth in a test tube of slanted agar. These larve 
when removed from the bottle showed their intestines to contain 
a dark substance which could be seen through the larval wall. 
After feeding for twenty-four hours the intestinal contents 
became colorless. Two days later the larve died. 
SERIES III 
In a, 0, and ec, of series II it was impossible to keep larve 
alive longer than two days on a pure culture of cholera vibrios, 
as there was a scarcity of nutriment in the agar and Dieudonné’s 
medium. 
