DIPTERA. 



71 



The fecundity of this fly is very great, for in the length of a 

 quarter of an inch, the envelope in which these small worms are 

 enclosed contains 2,000 of them. Therefore this ribbon, being two 

 inches and a half long, contains about 20,000 worms. 



The genus Stomoxys, though nearly related to the house-fly, 

 differs from it very much in habits. They live on the blood of 

 animals. The Stomoxys calcitrans is very common in these cli- 

 mates. Its palpi are tawny yellow, antennae black, thorax striped 

 with black, abdomen spotted with brown, and its trunk hard, thin, 

 and long. It deposits its eggs on the carcasses of large animals. 



The Golden Fly, Lucilia Ccesar, lays its eggs on cut-up meat, or 

 on dead animals. It is only three or four lines in length, of a golden 

 green, with the palpi ferruginous, antennae brown, and feet black. 



A species of this genus, the Lucilia hominivorax, has lately 

 obtained a melancholy notoriety. We are indebted to M. Charles 

 Coquerel, surgeon in the French imperial navy, for the most exact 

 information concerning this dangerous Dipteron, and the revela- 

 tion of the dangers to which man is liable in certain parts of the 

 globe. But let us first 

 describe the insect, 

 which is very pretty 

 and of brilliant colours. 



Fig. 52, taken from 

 M. Charles Coquerel' s 

 memoir, represents the 

 larva and the perfect 

 insect, as well as the 

 horny mandibles with 

 which the larvae is pro- 

 vided. It is rather more than the third of an inch in length, the head 

 is large, downy, and of a golden yellow. The thorax is dark blue 

 and very brilliant, with reflections of purple, as is also the abdomen. 

 The wings are transparent, and have rather the appearance of being 

 smoked ; their margins as well as the feet are black. 



This beautiful insect is an assassin ; M. Coquerel has informed 

 us that it sometimes occasions the death of those wretched con- 

 victs whom human justice has transported to the distant peniten- 

 tiary of Cayenne. 



Fig. 52. Lucilia hommivorax. 



