178 



TUBERCULOSIS 



deposited between the 6th and 14th days after infection. A number of preparations 

 made from the crop and intestinal contents of normal flies were examined but acid-fast 

 bacilli were never found." 



Experiment with B. tuberculosis in spjitmii. 



" A large number of flies were allowed to feed for 30 minutes on sputum, rich in 

 tubercle bacilli, which they took up greedily. Subsequently they were fed on non- 

 tuberculous sputum. In other respects the experiment was conducted in the same 

 way as the previous one, except that the contents of the crop were not examined." 



TABLE 25. Slioiving the results of an experiment with 

 sp/itujn containing B. tuberculosis. 



Time after 

 infection 



20 hours 

 50 ,, 

 69 „ 



90 >' 



i^ days 



.=1 >) 



9 

 10 



13 



No. of 

 fly 



1 



19 



Intestine 



+ 

 + 

 + (few) ... 



+ M 



+ 



o 



+ 



+ 



+ (i found) 



o 



o 



+ (2 found) 



o 



+ (few) ... 



Faeces 

 + (few) 



+ in 3 out of 6 samples 



+ in 2 out of 6 samples 



+ in I out of 3 samples 



o in many samples 



-1- I tubercle bacillus in many samples 



o in many samples 



o ,, ,, 



Intestinal contents emulsified and injected into a 

 guinea-pig. The animal was kept under observa- 

 tion for 8 weeks. After that time it was killed 

 and found to be healthy 



"This experiment .shows that under more natural conditions 

 tubercle bacilli may be found in the intestinal contents of flies 

 for at least four days. The fseces passed during that period are 

 also infected. The experiment is not, however, quite comparable 

 with the previous one since continual feeding on sputum gives 

 the flies diarrhoea." 



Wild Flies. Hofmann (1888) appears to be the only 

 observer who has examined ' wild ' flies for the presence of 



