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 



