174 THE HOUSE FLY—DISEASE CARRIER 
Ascaris eggs developed rapidly and were found in dif¬ 
ferent stages of development in the insects, thus prov¬ 
ing that the flies may serve as disseminators of the para¬ 
site. “Provided that the eggs attained the proper stage 
of development, the fly, acting simply as a carrier, 
might convey the parasite to man by falling into, or 
depositing its excreta on, the food.” 
