376 MEDICAL ENTOMOLOGY 



and the puparia are always found in the earth at some distance away, 

 or under the sides of the patch of dung. The puparium measures about 

 4'5 mm. in length and is dark brown in colour ; the fly usually hatches 

 out in five days, though sometimes as late as the eighth day. 



Weiss has studied the life history of irritaiis, variety weissii, from 

 Algeria ; its larval stage lasts five days, and the flies hatch out of the 

 puparia in another five days. Recently hatched flies will readily feed on 

 the human arm. 



Owing to the peculiar circumstances under which these flies lay their 



eggs it is necessary, in order to breed them, to watch freshly dropped 



cow dung in the field. If there are large number of 



Technique ^ ies on t ^ ie cow one or more f tne females will almost 



certainly alight on the dung and lay a number of eggs. 

 The dung should be transferred at once to a tray with some sand in it, 

 and taken to the laboratory. If it is regularly placed in the sun, the larvae 

 will be found in it in a few days ; they can be recognised by noting the 

 character of the posterior stigmata. 



The female flies will readily lay their eggs in test tubes, especially if 

 some fresh cow dung is placed at the bottom ; Weiss notes the same with 

 the Algerian species. In the case of exigua and minuta, for some 

 unknown reason, as often as not the eggs do not hatch out. Weiss does 

 not appear to have had any difficulty in rearing larvae from eggs laid in 

 dung in a test tube. 



The methods described in keeping and feeding Stomoxys should apply 

 equally well to Lyperosia. 



THE GLOSSININAE 



GENUS GLOSSINA, WIEDEMANN 



Narrow bodied, elongate flies of a yellowish to dark brown or black 

 colour, varying in size from 6 to 13' 5 mm. Width of frons in male from 

 one-third to one-half total width of head ; in female about one-half. 

 First two joints of antenna small, but the third joint long, and of a char- 

 acteristic shape, concave anteriorly, and ending in a forwardly directed 

 Point. Arista three jointed, the first two joints small and inconspicuous, 

 the third broadly elongated and slightly tapering at its extremity, 

 and adorned on its upper surface with from seventeen to twenty-nine 

 delicate curved, branching bristles. Proboscis long, projecting horizon- 

 tally forwards, and covered by the long hollowed out palps, which are 

 not swollen or pointed, but of uniform width throughout their length. 



