STOMOXrS CALCITRAXS AXD DISEASE 



201 



is possible that the pupae may exist through the winter, and the 

 larval stages mav also be found in warm situations durins the 

 winter. In studying the longevity of the adults Bishopp found 

 that they could be kept, when water and sugar svrup were supplied, 

 for twentv-three davs. Mitzmain found that a female flv can live 



• • • 



a maximum of at least seventy-two days and a male a period of 

 ninety-tour days. The length of the life-history depends on the 

 conditions with regard to temperature, moisture and nature of 

 food ; absence or presence of light also appears to influence the 

 rate of development. 



It is not intended to discuss the relation of S. calcitrans to 

 disease : the reader is referred to the excellent accounts of Brues, 

 Rosenau and Sheppard, and also those of Anderson and Frost*, for 

 an account "of their observations and experiments on the relation 

 of this fly to poliomyelitis. Its blood-sucking habits mav occa- 

 sionallv enable it to be the vector of the anthrax bacillus causinof 

 anthrax in cattle and malignant pustule in man-. Schuberg and 

 Kuhn (1911 ) have experimentally demonstrated that .S'. calcitrans 

 can infect animals with trypan"^ -TMes and spirochaetes*. 



:: anthrax bv 



miection 



:-a£e of one of two sheep 



