DIPTERA. 77 



The inhabitants of the Zambesi can, therefore, have no domestic 

 animal but the goat. When herds of cattle driven by travellers or 

 dealers are obliged to cross these regions, they only move them 

 during the bright nights of the cool season, and are careful to smear 

 them with dung mixed with milk ; the Tsetse fly having an intense 

 antipathy to the dung of animals, besides being in this season 

 rendered dormant by the lowness of the temperature. It is only by 

 such precautions that they are able to get through this dangerous 

 stage of their journey. 



The large blue Meat-fly, the familiar representative of the genus 

 Calliphora, is known to all by its brilliant 

 blue and white reflecting abdomen. This fly, 

 which is common everywhere, is the Calli- 

 phora vomitoria on which Reaumur has made 

 many beautiful observations, which we will 

 make known to our readers. 

 If we shut up a blue meat-fly in a glass 

 vase, as Reaumur did, and place near the 

 insect 

 day 



eggs thereon one after the other, in irregular 

 heaps, of various sizes. The whole of these heaps consist of about 

 two hundred eggs, which are of an iridescent white colour, and four 

 or five times as long as they are broad. In less than twenty-four 

 hours after the egg is laid the larvae is hatched. It is no sooner born 

 than it thinks of feeding, and buries itself in the meat with the aid 

 of the hooks and lancets with which it is provided. 



These worms do not appear to discharge any solid excrement, 

 but they produce a sticky liquid, which keeps the meat in a moist 

 state and hastens its putrefaction. The larvae eat voraciously and 

 continually ; so much so, that in four or five days they arrive at their 

 full growth. They then take no more nourishment until they are 

 transformed into flies. They are now about to assume the pupa 

 state. In this condition it is no longer necessary for them to remain 

 on the tainted meat, .which has been alike their cradle and their 

 larder, and where until now they were so well off. They therefore 

 leave it and seek a retreat under ground. 



The larva then assumes a globular form and reddish colour, loses 



original of this work is from a French translation : "Explorations dans 1'Interieur 

 de 1'Afrique australe, et voyages a travers le continent Sainte-Paul de Loanda a 

 1' Embouchure du Zambeze, de 1840 a 1846, traduit de 1'Anglais." Pages 93 95.' 

 8vo. Paris, 1859. -ED. 



ct a piece of fresh meat, before half a Fig. 54 ._Eggs of the Meat-fly, 

 is passed, the fly will have deposited its (.Catup/wra vomitoria). 



