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LIFE HISTORY OF HABRONEMA. 



were placed together in a jar with fresh dung from horse 

 " S." Fresh material always from the same horse was 

 added when necessary. The larvae of 31. vetustissima 

 matured and pupated first, and the flies emerged several 

 days before the house flies. In this way the two species 

 were easily separated. A fairly accurate count of the 

 number of worms in each M. vetustissima was made, the 

 worms being killed by heating after dissection of the fly 

 in order to facilitate the process. In the case of M. 

 domestica fewer worms were present and an accurate count 

 could be easily made. 



M. vetustissima. Twentj^-two flies (17 females and 

 5 males) were examined, all being heavily infected with 

 Habronema. Details of infection were as follows : — 



