RABIES AND FUNGAL SPORES 295 



another experiment a mouse was fed on bread soaked in an 

 emulsion of the flies' faeces passed about forty-eight hours after 

 infection and scraped from the walls of the cage. The mouse died 

 in two days and the organism was isolated from it. These experi- 

 ments showed that flies which have fed on the virus are capable 

 of infecting to so great an extent food mi which they settle and 

 feed that mice fed "U it became infected. 



Rabies. 



Experiments with a view to discovering whether flies would 

 carry the virus of rabies obtained during the larval state have 

 been earned out by Fermi (1911). In the first series of experi- 

 ments the author fed fly larvae on the brains of rabies cases and 

 then tested their virulence by emulsifying and injecting subcu- 

 taneously. In a second series a fixed virus and fly larvae were 

 rubbed into an emulsion and likewise injected subcutaneously. 

 The results indicate that rabies virus cannot be transmitted 

 through fly larvae. It appears that the fly emulsion has an 

 attenuating effect upon a fixed virus, either through its direct 

 action upon the virus or through its indirect action upon the 

 organism. It possesses no absolute lyssicidal power since a virus 

 mixed with fly larvae emulsion is found to be virulent when 

 administered subdurally. 



Fungal spores. 



In the experiments of Giissow, already mentioned, it was shown 

 that flies normally cany the spores of moulds such as Penicillium, 

 Eurotiuni, Mucor, yeasts, etc. Consequently their fi'equent in- 

 fection of food materials, which may be observed if attention is 

 given to the matter, is readily understood. Gayon (1903) also 

 cultivated several species of moulds from flies which he caught 

 and dropped into nutrient gelatin. Experimenting with yeasts, 

 Graham-Smith (1910) found that the yeast organisms did not 

 appear to survive for more than a few hours on the legs and wings, 

 but that they could be found in cultures of the crop and intestine 

 for at least three days, and were present in the faeces 48 hours 

 after the fly had been infected. 



Cobb (1906) made studies of the extent to which flies trans- 

 ported the spores of a fungus attacking sugar cane. The feet of 



