14 HOUSEHOLD INSECTS 



in proportion to those feeding at the breasts was as 25 

 to 1 in New York City. He feels sure that the house-fly 

 is responsible for a large part of this mortality among 

 bottle-fed infants, due to the infection of the milk by the 

 flies with the germs of infantile diarrhea, and the like. 



There seems a possibility that the house-fly may convey 

 the plague bacillus from infected rats or human beings 

 to other individuals. The bacilli of leprosy have been 

 found in the alimentary canals and feces of flies after they 

 have been allowed to feed on leprous sores. Whether 

 these bacilli, if lodged by the fly on the person of an un- 

 infected individual, would enter the system of that in- 

 dividual and produce the disease is not known. At all 

 events, one would not care to have a fly carrying these 

 bacilli alight on one's food or person. 



Anthrax bacilli are also carried about by flies, and Howe, 

 according to Howard, has shown that the purulent con- 

 junctivitis of the Egyptians is spread by the house-fly. 

 House-flies are especially dangerous as agents of the dis- 

 semination of disease germs because they are fond of all 

 kinds of human foods, both liquid and solid, and, moreover, 

 are very restless, active insects, traveling quite extensively 

 and flitting from place to place with considerable rapidity. 

 "In the course of a few moments a single fly may crawl 

 over human or other excrement, sip from a glass of milk 

 or water, and merrily chase across a dish of mashed 

 potatoes, or other human food. It may visit a dead and 

 decaying animal, or sport about the mouth of a reeking 

 sewer, and in the next five or ten minutes sip from the 

 edge of a glass of jelly or alight in the sugar bowl." As 

 an English author wrote many years ago, the house-flies 

 become a great nuisance "both from their numbers and 



