CHAPTER XXIII 



THE DISSEMINATION OF OTHER DISEASES BY FLIES 



Anthrax 



In considering the relation of flies to anthrax several fects 

 should be borne in mind. As early as the eighteenth century it 

 was believed that anthrax might result from the bite of a fly, and 

 the idea has been used by Murger in his romance Le Sabot Rouge. 

 A very complete historical account of these earlier ideas is given 

 by Nuttall (1899). Most of the instances in support of this belief, 

 however, that flies may carry the infection of anthrax, refer to 

 biting flies. As I have already pointed out, M. domestica and 

 such of its allies as F. canicidaris, C. erythrocephala, C. vomitoria 

 and Lucilia caesar are not biting or blood-sucking flies. The 

 nearest allies of M. domestica which suck blood in England are 

 S. calcitrans, Haematohia stimulans Meigen and Lyperosia irri- 

 tans L. ; the rest of the blood-sucking flies which may be considered 

 in this connection belong to the family Tabanidae, including the 

 common genera Haematopota, Tabanus, and Chrysops. These 

 biting and blood-sucking flies live upon the blood of living rather 

 than dead animals. But it is from the carcases and skins of 

 animals which have died of anthrax that infection is more likely 

 to be obtained, and I believe that such flies as the blow-flies 

 (Calliphora spp.) and sometimes 31. domestica and Lucilia caesar 

 which frequent flesh and the bodies of dead animals for the 

 purpose of depositing their eggs and for the sake of the juices, 

 are more likely to be concerned in the carriage of the anthrax 

 bacillus and the causation of malignant pustule than are the 

 blood-sucking flies. Consequently, as M. domestica and its allies 



