82 LIFE HISTORY OF HABRONEMA. 



cage and fed on moistened raisins. They were offered 

 warm human saliva in a welled slide daily without result 

 until November 28th, when two H. muscce escaped, only 

 two flies being alive on this date, though they died during 

 the day. All these flies were heavily infected with 

 Habronema, over 80 being counted in one fly. No 

 specimens of H. megastoma were identified in this batch. 



Experiment II. — On November 30th, six M. 

 vetustissima were placed in a cage and treated in the same 

 manner as in Experiment I. On 1st December, one 

 H. muscce escaped into warm human saliva. These flies 

 also died off rapidly, and no more nematodes escaped. All 

 flies were heavily infected with Habronema, both species 

 being present. 



Experiment III. — From 10th to 12th December about 

 twelve M. vetustissima bred on infected material were 

 placed in a cage. On December 13th, five flies were alive, 

 and during the day a total of 49 Habronema (chiefly, 

 H. muscce) escaped into warm human saliva. On December 

 14th, all the flies were dead. 



Escajje of Habronema from M. domestica. 

 Experiment I. — On 13th and 14th January, 1920 

 about ' 20 house flies bred on infected horse dung were 

 placed in a cage and fed on moistened raisins. A drop of 

 human saliva in a well-slide Avas placed in the cage on a 

 slab of stone which had been previousl}^ warmed to about 

 40° C. The slide was withdrawn and examined from time 

 to time, more saliva being added and the slab of the stone 

 heated again. It happened occasionally that the saliva 

 dried up in the well-slide before examination, and when this 

 occurred it was difficult to determine the species of any 

 which might have escaped, such worms being recorded 

 merely as Habronema. The total number of nematode?, 

 escaping each day is given : — 



January 14th . . none escaped 



January 15th .. 2 H. muscce and 1 Habronema sp. escaped 



January 17th . . 1 H, muscce and 2 Habronema sp. escaped 



January 19th . . 10 Habronema sp. escaped 



January 20th . . 24: H. muscce escaped 



January 21st . . 5 H. muscce escaped 



Januaiy 22nd . . none escaped 



January 23rd . . none escaped 



Total number of Habronema 51. 



