ANTHRAX 185 



*' Cultures were made on agar from 95 flies which emerged." 

 Cuhures from 11 out of 14 newly hatched flies showed B. antliracis {j^"lu) 

 ,, ,, 48 ,, 62 flies I day old ,, ,, ,, 



„ 2 „ 8 „ 3 days „ „ ,, (25'V,,) 



„ I „ 6 „ 4 „ „ „ (•''>7o) 



„ I „ 5 „ ^> „ „ » (_^o%,) 



" Positive results were obtained from 63 (66 "/q) out of the 95 flies examined. A 

 few of the flies which emerged were kept in a clean cage without food and died in a 

 few days. After they had been dead for some weeks cultures were made from three 

 of them. B. aiitliracis was found in cultures from two." 



In another series of experiments (p. 332) half grown larva; of 

 C. erytJirocephala and L. ccssar were allowed to feed on the bodies 

 of guinea-pigs which had died of anthrax. 



"The larvae pupated in 10 — 15 days and the flies began to emerge in 20 days. In 

 order to avoid the possibility of the flies re-infecting themselves after emerging the 

 pupre were removed to clean cages and placed on clean sand. In some cases before 

 the preparation of cultures the flies were sterilized in various ways, while in other 

 cases no sterilization of the exterior was attempted. Sometimes the flies were killed 

 shortly after emerging, while on other occasions they were kept for some hours or 

 days. In the latter case they were fed on syrup. 



" Cultures on agar were prepared in the way previously described from the intestinal 

 contents of 511 flies, 170 C. erythrocephala and 341 L. cofsar, which emerged from 

 larvae ^'hich fed on the body of a guinea-pig dead of anthrax. Only three colonies 

 were met with which resembled in any way those produced by B. anihracis. By 

 subcultures they were proved not to be those of B. ajit/n-acis." 



These experiments show that flies {M. doniestica and 

 C. erytJirocephala) which hatch out from larva; which have fed 

 on material contaminated with anthrax spores are heavily 

 infected on emerging, and remain infected for several days. 

 They can infect surfaces on which they walk, and fluids on 

 which they feed and deposit infected faeces. On the other hand 

 flies (C erytJirocepliala) which develop from larvae which have fed 

 on non-spore bearing anthrax bacilli are not infected. 



Wild Flies. Dickinson states that "Billings (1898) found 

 anthrax bacilli in the stomachs and intestines of flies collected 

 from the body of an infected steer." 



Summary. 



Experiments have shown that flies {AI. domestica and 

 C. erythrocephala) infected with the spores of B. antliracis may 

 carry and distribute the organism for many days, and that the 



