(157) 



398 C. GORDON HEWITT. 



access to a cholera intestine, and also from flies caught in a 

 cholera post-mortem room. Uffelmann (1892) fed two flies on 

 liquefied cultures of the cholera spirillum, and after keeping 

 one of them for an hour in a glass he obtained 10,500 

 colonies from it by means of a roll culture ; from the other, 

 which was kept two hours under the glass, he obtained 

 twenty-five colonies. In a further experiment he placed one 

 of the two flies similarly infected with the spirillum in a glass 

 of sterilised milk, which it was allowed to drink. The milk 

 was then kept for sixteen hours at a temperature of 2021 C., 

 after which it was shaken, and cultures were made from it; 

 one drop of milk yielded over one hundred colonies of the 

 spirillum. The other fly was allowed to touch with its pro- 

 boscis and feed upon a piece of juicy meat that was sub- 

 sequently scraped. From one half of the surface .twenty 

 colonies, and from the ofcher half one hundred colonies, of the 

 spirillum were obtained. These experiments show the danger 

 which may result if flies having access to a cholera patient, and 

 bearing the spirillum, have access also to the food. Macrae 

 (1894) records experiments in which boiled milk was exposed 

 in different parts of the gaol at Gaya in India, where cholera 

 and flies were prevalent. Not only did this milk become 

 infected, but the milk placed in the cowsheds also became 

 infected. The flies had access both to the cholera stools and 

 to such food as rice and milk. 



These foregoing experiments prove beyond doubt the ability 

 of flies to carry the cholera spirillum, both internally and 

 externally, in a virulent condition, and to infect food. 



4. Tuberculosis. 



Although it may be considered to be hardly necessary to 

 introduce flies as a means of disseminating the tubercle 

 bacillus, it has, nevertheless, been proved experimentally 

 that they are able to carry the bacillus in a virulent condition. 

 As early as 1887 Spillman and Haushalter carried on experi- 

 ments in which they found the tubercle bacillus in large 



