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 bams 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. 
