152 THE HOUSE FLY—DISEASE CARRIER 
bacteria could be isolated from their dejections. In 
the same year M. Simmonds studied the flies in a hos¬ 
pital in Hamburg, especially those present in the post¬ 
mortem room, where many bodies and intestines of 
persons dead of cholera were lying. He was able to 
isolate cholera vibrios from the first fly caught. He 
had the room cleaned at once, and after this was unable 
to obtain cholera germs from flies caught. He found 
that healthy, active cultures could be made from flies 
for an hour and a half after they had visited infected 
material. 
Much the same work was done in that year and sub¬ 
sequent years by Uffelmann, and in 1905 Chantemesse 
succeeded in isolating cholera vibrios from the feet of 
flies seventeen hours after they had been contaminated. 
In 1908 Ganon stated that flies can transmit infection 
for at least twenty-four hours after a meal of infected 
material, and showed that that period is sufficient to 
allow them to be carried for a long distance in railway 
trains. Nuttall and Jepson point out that the various 
experiments made during this period gain in value from 
the fact that the investigators were to a large extent 
ignorant of the work done by others, and they add that 
a number of authors, without contributing any personal 
evidence on the subject, express their conviction that 
the house fly carries cholera. They consider that the 
body of evidence which they present as to the part 
played by flies in the dissemination of cholera appears 
to be quite convincing. 
An interesting and important piece of work in this 
