that spread Disease. 



29 



one's hands and face, the lesser house-lly remains mostly on tlie 

 \ving, Hying about with a curious darting movement beneath the 

 gas-bracket or electrolier in the middle of the bedroom. The 

 lesser house-fly appears earlier in the year than the common 

 house-fly, and persists later, being still found in dwelling rooms 

 as late as November. The lesser house-fly is closely related to 

 the latrine-fly or privy-fly, Fannia scalaris Fabr., but the latter, 

 although a dangerous disseminator of intestinal disease in villages 

 and camps, is scarcely a house-fly ; it rarely enters houses. 



Fig. 8. — Common House-Fly, 



Ahisca domestica, female, x 6 ; largely responsible for the spread of typhoid fever 



and summer diarrhoea. 



Shown in the same case are specimens of two other house-flies, 

 Muscina stahulans Fin., a large fly, not frequent in its occurrence, 

 and Stomoxys calcitrans Linn., commonly termed the stable-fly. 

 This last is a biting, blood-sucking fly, common in the country and 

 in subui'bs, and met with sometimes in the middle of large towns. 

 People who do not discriminate between the different kinds of 

 house-fly imagine, when bitten by a Stomoxijs, that it is an ordinarj' 

 house-fly that has become particularly vicious. Critical examination 



