House-Flies or Typhoid-Flies 69 



colonies of the germs could later be recovered from 

 the food. As with the typhoid germs milk seems to 

 be a particularly good medium for the develop- 

 ment of the cholera germs. In several of the ex- 

 periments that have been made along this line the 

 milk has been readily infected by the flies visiting it. 



Of course an outbreak of cholera is of rare 

 occurrence in our country, but unfortunately this 

 is not so in regard to some other intestinal diseases 

 such as diarrhea and enteritis which annually 

 cause the death of many children, especially bottle- 

 fed babies. Those who have made close studies of 

 the way in which these diseases are disseminated 

 are convinced that the flies are one of the most 

 important factors in their spread. 



It has long been observed that flies are par- 

 ticularly fond of sputum and will feed on it on the 

 sidewalk, in the gutter, the cuspidor or wherever 

 opportunity offers. It is well known, too, that 

 the sputum of a consumptive contains myriads 

 of virulent tubercular germs. A fly feeding and 

 crawling over such material must necessarily get 

 some of it on its body, and as it dries and the insect 

 flies about the germs will be distributed through 

 the air, possibly over our food. It has been shown 

 that the excretion from a fly that has fed on tuber- 

 cular sputum contains tubercular bacilli that may 



