X, B, 5 Roberg: Bacterial Infections 819 
predominating organism. On examination none of the plates 
showed the presence of B. typhosus. Constantly found was a 
typhoidlike organism, provisionally called Bacillus “A.” Bacil- 
lus prodigiosus was also found. The strong ammoniacal odor 
was liberated by Bacillus “A.” 
Pupz were taken from the mash; their exterior was steri- 
lized, and then crushed and inoculated on plates of McConkey’s 
medium. These plates showed profuse growths of Bacillus “A” 
and B. prodigiosus, but B. typhosus could not be recovered. 
Similar examination of the larvze before pupation resulted, 
also, in the isolation of Bacillus “A,” but not of B. typhosus. 
A newly emerged fly was chloroformed, and its exterior was 
sterilized. The intestines were removed aseptically, mashed, 
and inoculated on to plates. There was an absence of B. typho- 
sus. Bacillus “A’’ was recovered. 
In the second series cultures were made from the shells of- 
eggs from which the larve had just hatched. These cultures 
showed growths of the following organisms: Bacillus “A,” B. 
proteus vulgaris, B. prodigiosus, and a streptococcus. 
Larve which had fed upon a sterile mash were secured, and 
their surfaces were sterilized. When mashed and inoculated 
upon plates, they showed growths of Bacillus “A,” B. prodigio- 
sus, and a lactose-fermenting organism provisionally called 
Bacillus “B” No. 3. 
In the third series the eggs were first sterilized in lysol and 
then placed upon sterile agar and fed with sterile human blood - 
to which were added typhoid cultures. The larvze secured from 
this mixture, when their surfaces were sterilized, gave pure 
cultures of B. typhosus when crushed and inoculated upon plates. 
Other larve were removed from this agar-human blood and 
typhoid mixture, placed upon sterile sand, and allowed to pupate. 
These pupz showed upon examination that they contained pure 
cultures of B. typhosus when crushed. 
Ledingham’s conclusions are summarized as follows: 
Although typhoid bacilli were liberally supplied to the larve, 
B. typhosus could not be isolated from the pup or imagines, 
until recourse was had first to the disinfection of the eggs. 
When unsterilized eggs were used there appeared constantly 
a typnoidlike bacillus. This typhoidlike bacillus, called Bacil- 
lus “B,” thoroughly adapts itself to the conditions in the interior 
of the larve, pupz, and imagines. 
There was, also, evidence that B. typhosus, when isolated 
from the interior of larve fed upon typhoid bacilli under ideal 
