316 THE SPREAD OF INTESTINAL WORMS BY FLIES 



which are too large to be ingested by the flies, could be carried 

 externally by the flies and that food (sugar) could be infected. 



The careful experiments of this investigator show that, under 

 experimental conditions, the eggs of the following parasitic worms 

 may be carried by Musca domestica : Taenia solium, T. serrata, 

 T. marginata, Dipylidium caninum, Dibothriocephalus latusC^). 

 Oxyuris vermicidaris, Trichuris (T^'ichocephalus) trichiuris, both 

 internally and externally; Necator americanus, Ankylostonia 

 caninum, Sclera stomuin eqimiuni, Ascaris megalocephala, Toxascaris 

 limbata (= Ascaris canis e.p.), Hymenolepis dirninuta externally 

 only. 



The practical significance of the results of the aforementioned 

 studies of the relation of Musca domestica and such of its allies as 

 have similar coprophagous or coprophilous habits is great. The 

 necessity of preventing flies from gaining access to faeces or tape- 

 worm segments is most clearly demonstrated and the possibility 

 of flies infecting food with tape-worm eggs will undoubtedly furnish 

 an explanation in many otherwise obscure cases of infection. 



