REPORT OF THE STATE ENTOMOLOGIST I908 29 



for the transmission of typhoid fever are fingers, food and flies,"" 

 the authors holding the last to be the most important. 



The possibilities of transmitting typhoid fever are appalling to 

 the layman when it is remembered that the germs of this disease 

 may be in the system several weeks before diagnosis is possible, 

 continue in numbers six to eight weeks after apparent recoverv 

 and in exceptional cases may be discharged from the system during 

 a period of several years. There are authentic records of a patient 

 distributing these germs for 17 years and being the incipient cause 

 of 13 cases during 14 years of that period. Furthermore, Dr ^i. 

 A. \'eeder of Lyons cites a case wdiere typhoid fever was perpetu- 

 ated from year to year in a locality, ascribing it to a physician 

 recommending the burial of all typhoid excreta and the execution 

 of this direction by a favorite nurse. It is well known that soil 

 infected by these germs may be the origin of new cases, and Dr 

 \'eeder significantly observes that the annual recurrence of typhoid 

 fever in the above mentioned locality ceased with the death of the 

 two parties mentioned above and a change in the method of dis- 

 posing of typhoid discharges. 



The evidence against this insect may therefore be summed up 

 briefly as follows: \'iruleiit typhoid bacilli have been found upon 

 the legs and within the body of this insect, persisting in the latter 

 case for 2^ days. A number of serious outbreaks have been ob- 

 served by competent physicians, where infection through a com- 

 mion water or food supply did not satisfactorily explain the out- 

 break. This positive evidence, while not establishing beyond all 

 question the culpability of the fly, is further supported by the 

 opinion of a number of reputable physicians who have had exten- 

 sive experience with outbreaks of this character. 



The evidence showing that flies may play an important part in 

 the diffusion of cholera is, according to Dr Xuttall, absolutely con- 

 vincing. He cites experiments showing that cholera bacilli may 

 be found on flies in large numbers, while they may occur in the 

 dejecta within 17 liours after feeding and as late as four days. 

 Infected flies have been given access to milk and cholera culture^ 

 made therefrom. 



Typhoid fever anrl cholera, while both serious infections, are by 

 no means the only diseases which may be conveyed by flies. Cer- 

 tain forms of diarrhoea and enteritis are unrloubtedly due to spe- 

 cific germs, and there is no reason why the bacilli causing these 

 infections mav not be carried as easilv and in the same wav as 



