170 THE HOUSE FLY— DISEASE CARRIER 



tigator found that flies bore living gonococci upon their 

 feet three hours after they had been soiled with secre- 

 tion, since they infected sterilized plates with which 

 they came in contact. 



Nuttall and Jepson conclude their consideration of 

 ophthalmia with the following statement: "The evi- 

 dence regarding the spread of Egyptian ophthalmia by 

 flies appears to be conclusive, and the possibility of 

 gonorrheal secretions being conveyed by flies cannot be 

 denied." 



Diphtheria 



Nuttall and Jepson have been able to find only one 

 reference to the dissemination of Bacillus diphthericc 

 by flies. They state that Dickinson (1907) cites Smith 

 (1898) as having tried the of t-repeated 'type of experi- 

 ment of allowing house flies to walk over infected ma- 

 terial and then over sterile media. A positive result 

 was obtained as a matter of course. The authors state 

 that there is no evidence that under natural conditions 

 flies have anything to do with the spread of diphtheria, 

 but indicate that it is of course conceivable that they 

 may convey the infection under suitable conditions. 



Small-pox 



The only published account of the possible relation 

 of flies to small-pox cited by Nuttall and Jepson is 

 taken by them from a paper by Hervieux, read June 5, 

 1904, to the Academy of Medicine at Paris, in which 

 he states that Laforgue at a locality in the province of 

 Constantine observed that during an epidemic of small- 



