99 
. Larvae were found to remain alive in the bodies of dead 
flies for several days if loss of moisture was prevented. 
Tue LIFE-HISTORY or Habronema megastoma 
(Rudolphi, 1819). 
The methods adopted in this investigation have alread 
been mentioned. The embryos were sometimes obtained from 
the contents of the submucous tumours and sometimes from the 
gravid female. 
Embryos of H. megastoma.—The embryos are enclosed in 
a thin shell or membrane. They are doubled on themselves 1n 
the shape of the letter U, the tail coming to lie close to the 
head. The shell measures from 43:3 p to 53:3 p long by 
ll6 p to 13:3 » wide. The widest portion of the embryo 
measures 6'6 p. : 
e embryos when placed in saline solution and tap water 
behave in the same way as those of H. muscae. When they do 
break away from the shell they remain bent in the shape of 
encysted. From four to five days later these larvae had 
developed into the final larval stage. The atmospheric 
fly. The proboscides of many of the flies were seen 
"alyz When these flies were examined some days later 
the larvae were found to be less active than when first making 
their appearance in the head and proboscis. 
- been observed that if flies die when the larvae are 
m an early stage of development these larvae quickly die, but 
if the final larval stage has been reached the larvae live for 
