X, B, 5 Roberg: Bacterial Infections 8321 
vive long enough in the larval intestine to appear in the imagines. 
Morgan’s bacillus, which is often a commensal in the intestine 
of larve, constantly persists in the intestine of the imagines,- 
along with other nonlactose-fermenting organisms. The spores 
' of B. anthracis, also, persist. 
SERIES 3 
To ascertain whether different substances on which larve 
were fed in any way favor the persistence of different bacteria, 
separate boxes were prepared and the following sterilized sub- 
stances were placed therein: namely, in the first cooked meat 
and rice, in the second human feces, and in the third box un- 
sterilized human feces. Eggs and larve grown on sterilized 
food were placed in these boxes and infected separately with 5. 
typhosus, B. enteritidis, Morgan’s bacillus, and B. prodigiosus ; 
one box was uninfected as a control. : 
When the flies emerged the intestinal bacteria were exam- 
ined. Growths on plates of McConkey’s medium showed sev- 
eral nonlactose-fermenting colonies, none of which proved to 
be B. typhosus. Morgan’s bacillus could be isolated from flies 
from the different foods. 
Different foodstuffs, then, apparently exercise no influence 
on the persistence of bacteria in.the intestines of newly emerged 
flies. 
As previously stated, observations and attention have been 
particularly centered upon the larger and easily visible species 
of flies. This is especially true in Manila, where it is stated 
that a scarcity exists in flies. The scarcity of flies in Manila 
applies only to-the larger species and not to the minute mem- 
bers of the family Phoride, which are abundant. No doubt 
as a result of their minuteness they have been overlooked. 
These minute Phoridex, then, having biological features simi- 
_ lar to the common large species of Diptera, should be regarded 
as a menace in the spread of bacterial infections. 
The members of this group lay their eggs and breed in putre- 
fying material, and if human feces are available, they are the 
more preferable. ; 
Even though sanitary regulations be severe in regard to the 
disposal of human feces, and suitable so-called fly-proof sanitary 
pails be recommended or furnished by the Bureau of Health, 
these minute flies nevertheless gain ready access to the feces. 
Should the feces be contaminated with pathogenic bacteria, as 
they so frequently are from cholera carriers or active cholera 
cases, and from infections where pathogenic organisms are dis- 
