Other Arthropods as Simple Carriers 163 



in the larval and pupal stages, and that the adults which have been 

 observed in heated stables in the dead of winter were bred out in 

 refuse within the warm barns and were not hibernating adults. 



Graham-Smith (1913) states that although the stable-fly fre- 

 quents stable manure, it is probably not an important agent in 

 distributing the organisms of intestinal diseases. Bishopp makes the 

 important observation that "it has never been found breeding in 

 human excrement and does not frequent malodorous places, which 

 are so attractive to the house-fly. Hence it is much less likely to 

 carry typhoid and other germs which may be found in such places." 



Questions of the possible agency of Stomoxys calcitrans in the trans- 

 mission of infantile paralysis and of pellagra, we shall consider later. 



Other arthropods which may serve as simple carriers of patho- 

 genic organisms It should be again emphasized that any insect which 

 has access to, and comes in contact with, pathogenic organisms 

 and then passes to the food, or drink, or the body of man, may serve 

 as a simple carrier of disease. In addition to the more obvious 

 illustrations, an interesting one is the previously cited case of the 

 transfer of Dermatobia cyaniventris by a mosquito (fig. 81-84). 

 Darling (1913) has shown that in the tropics, the omnipresent ants 

 may be important factors in the spread of disease. 



