STRUCTUEE, DEYELOraiENT, AND BIONOMICS OF HOUSE-FLY. 399 
numbers in the intestines of flies from a hospital ward, and 
also in the dejections which occurred on the windows and 
walls of the Avard. Hoffmann (1886) also found tubercle 
bacilli in the excreta of flies in the room where a patient had 
died of tubei’culosis, and he also found the bacilli in the 
intestinal contents. One out of three guinea-pigs which were 
inoculated Avith the intestines died ; two inoculations Avith the 
excreta had no effect, Avhich led him to believe that the bacilli 
became less virulent in passing through the alimentary tract. 
But Celli (1. c.) records experiments in Avhich tAVO rabbits 
inoculated with the excreta of flies fed with tubercular sputum 
developed the disease. HayAvard (1904) obtained tubercle 
bacilli in ten out of sixteen cultures made from flies Avhich 
had been caught feeding on bottles containing tuberculous 
sputum. Tubercle bacilli Avere also recovered from cultures 
made from the faeces of Hies Avhich had fed in the same 
manner, Avhich apparently caused a kind of diarrhoea in the 
flies, and they died from tAvo to three days afterwards. 
Fmces of flies fed on tubercular sputum Avere rubbed up in 
sterile Avater and injected into the peritoneal cavity of guinea- 
pigs, which developed tuberculosis. Buchanan (1. c.) alloAved 
Hies to Avalk over a Him of tubercular sputum and then over 
agar; a guinea-pig died of tuberculosis in thirty-six days by 
inoculating it with the resulting culture. 
o. Ophthalmia. 
Flies have been suggested as playing an important part in 
the spread of conjunctivitis, especially Egyptian ophthalmia, 
and although, so far as I have been able to discoA^er, Ave have 
no bacteriological evidence in favour of the belief, the circum- 
stantial evidence is sufficiently strong to Avarrant it. 
In speaking of its occurrence at Biskia, Laveran (1880) 
says that in the hot season the eyelids of the indigenous 
children are covered Avith Hies, to the attentions of Avhich 
they submit; iu this AAmy the infectious discharge is carried 
on the legs and probosces of Hies to the healthy children. 
