DISSEMINATION OF TUBERCULOSIS BY FLIES 269 



crop and intestinal contents for at least seven days. The spores 

 remained in a living condition in the vomit and faecal deposits for 

 six days or longer. Cultures were also made from drops of sugar 

 after the flies had been allowed to feed upon them and anthrax 

 bacilli were obtained on the tenth day after the flies had fed. It 

 was also shown in another experiment that the anthrax spores 

 may remain alive for at least twenty days upon the legs and 

 wings and in the intestinal contents of the fly and that faeces 

 passed fourteen days after infection contained living spores. Dried 

 faeces and vomit were shown to contain the spores in a vital con- 

 dition for twenty days. Cultures were obtained from the bodies 

 of dead flies four hundred and twenty-eight days after death and 

 proved to be virulent by animal inoculations. 



In connection with the experiments of Faichnie and (jthurs on 

 flies bred from larvae infected with B. typhosus the results of 

 Graham-Smith's experiments with B. untlirucis are of interest. 

 The larvae of C. erythrocephala were fed on meat infected with 

 anthrax spores. The flies bred from these larvae were heavily 

 infected for at least two days after emerging. In a single series 

 of experiments B. anthracis could not be cultivated either from 

 the limbs or intestinal contents of flies more than fifteen or 

 nineteen days old. It was found that flies were able to infect, 

 during the first two days after emerging, materials over which 

 they walk, and to deposit infected faeces. 



In a further report Graham-Smith (1912) states that he finds 

 that a large proportion of Musca domestica which develop from 

 larvae infected with the spores of B. anthracis are infected. 



These results confirm the suggestion made by Joseph (1887) 

 and later by Nuttall {I.e.) that the non-biting flies, when infected, 

 may spread anthrax by depositing bacilli upon wounds or food and 

 they have a significant bearing upon the spread of the disease 

 among domestic animals and the production of malignant pustule 

 in man. 



Tuberculosis. 



With the proven existence of so many factors contributing to 

 the dissemination of the tubercle bacillus, the significance of ex- 

 periments of a positive nature indicating the ability of flies to 



