SÉANCE DU 16 NOVEMBRE 1035 



very coprophagous, must be suspected as one of tlie agents of dissémi- 

 nation of germs from the naso-pharyngeal or pulmonary tracts (diph- 

 theria, cerebro-spinal meningitis, influenza, tuberculosis, etc.). It 

 is more often found feeding in sputa than in excréments. 



b) Action of the other species. — Fcmnia canicularis and se alaris play 

 much more important parts in the dissémination of intestinal germs. 

 Thèse Aies are frequently seen in excréments and food. specially fruit. 

 The other kinds, which are only occasionally found in houses {Muscina 

 Pollenia or Cluster tly), do not deserve particular attention. 



3. Flies found on dead bodies (blow-fly : Calliphora; green bottle : 

 Lucilia, Phormia, etc.; flesh-fly, Sarcophaga). — Thèse flies live in the 

 open air on bodies or putrified matter, as well as on excréments and 

 refuse. At the front thèse /lies are found especiaUy in feeal matters and 

 garbage. 



They play a most important part in the dissémination of patlfogenic 

 agents which are found especially on fresh excréments. 



4. Action of Flies in the Transportation of germs. — The greatest 

 interest ought to be drawn to détermine the mode and conditions of the 

 pathogenic action of the différent kinds of flies. 



The majority of the germs which are gathéred by the fly undergo no 

 altération when they are eliminated in the fèces, and they can Ihus be 

 diffused through the intestinal tract of thèse insects. This dissémina- 

 tion, however, seems to be limited to a certain extent. 



a) Flies usually do not defecate on food (experiments of Marchoux on 

 the bacillus ôf Stefansky). However, they may regurgitate part of 

 their food wherever they are. 



b) Cysts of intestinal protozoa (dysenterie amebœ, Lamblia) do not 

 resist to desiccation in the fèces of flies (experiments of Roubaud). 

 This is doubtless also the case in a great number of the germs found in 

 dried fèces of thèse insects. 



The mechanical dispersion through the tarsus, the oral lobes of the 

 trunk seems to be more fréquent than the dispersion through the intes- 

 tinal tract ; it is probably more difficult for the carriage of cysts of pro- 

 tozoa than for microbian éléments. 



While men defecate, many flies may gather around the anus and may 

 contaminate the surrounding skin. In those conditions is the transmis-' 

 |., sion per rectum of intestinal germs possible? 



5. Myiases. — Most of the Flies mentioned above, and especially 

 those with sarcophagous larvse, light on dirty dressings and may deposit 

 their eggs on the wounds. They may also give rise to intestinal 

 myiases. 



Biologie. Compte.s rendus. — 1918. T. LXXXI. 72 



