
AMERICAN MUSECOM- GOIDE, LEAFLETS 

THE FILTH FLY AND DISEASE 
Musca domestica is not only a pest but a serious menace to health 
on account of the likelihood that it may carry filth from the unsavory 
places which it frequents to food. The foot of the fly is tipped with 
claws and soft pads on which there is ample room for great numbers 
of microbes to be transplanted; and, as a matter of fact, if a fly be 
allowed to walk over the surface of a properly prepared bacterial 
culture plate, the path over which it travels is marked by numerous 

Fig. 9 
colonies of bacteria, each developed from a single germ planted 
there by the foot of the insect. Even more serious, perhaps, is the 
danger that disease germs ingested by a fly from privy contents, or 
other infected material, may be voided in its excrement (fly specks) 
or in small droplets which are regurgitated by the insect. Experi- 
ments have shown that many kinds of disease germs may pass 
through the intestines of the fly and be discharged in its excrement in 
an active and virulent state. 
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