CARRIAGE OF DISEASE 169 



and found on their feet bacteria which were similar to 

 those found in the conjunctival secretion. 



At the time when Doctor Howe told the writer of 

 this paper, the latter was so filled with the idea that 

 horse manure was far and away the most abundant 

 producer of house flies that, inasmuch as there are com- 

 paratively few horses in the Nile Valley, he was in- 

 clined to suspect that the fly concerned in the carriage 

 of this disease as pointed out by Doctor Howe might 

 be some other species breeding by preference in camel 

 dung or perhaps in some other substance. He there- 

 fore sent to Egypt and secured specimens of the flies 

 commonly swarming about the eyes of ophthalmic pa- 

 tients, and on their receipt in Washington they were 

 readily determined as Musca domestica by Mr. D. W. 

 Coquillett of the Bureau of Entomology. 



Nuttall and Jepson show that Budd, as early as 1862, 

 considered that it was fully proven that flies served as 

 the carriers of Egyptian ophthalmia, and Laveran, in 

 1880, writing of Biskra, says the same. These writers 

 also point out that Braun (1882), Demetriades (1894) 

 and German (1896) agree that gonorrheal and other 

 infections of the eye may be carried by flies. They 

 state that Welander (1896) observed an interesting 

 case where an old bedridden woman in a hospital be- 

 came infected. It seems that her bed was alongside 

 that of another patient who had blennorrhea, but that 

 a screen which did not reach to the ceiling separated 

 the beds. Thus all means of infection except through 

 the agency of flies was apparently absent. The inves- 



