OVO-VIVIPAROUS INSECTS. 109 



naturalists with respect to the scorpion's being ovo- 

 viviparous, have been recently verified by Leon 

 Duibur*, a living French naturalist, distinguished 

 for acuteness and accuracy. 



In the case of insects, it was first discovered by 

 Redi, the father of experimental entomology, that, 

 though the greater number of flies lay eggs, some 

 also bring forth their young alive, and he was tlience 

 led to put the question, whether such flies, under dif- 

 ferent circumstances of temperature, do not sometimes 

 produce young, and at other times deposit eggsf. 

 He might as well, says Reaumur, have asked whe- 

 ther, in certain circumstances, a hen, instead of laying- 

 eggs, should bring forth chickens. The fact, on the 

 contrary, has been ascertained by Reaumur, and re- 

 cently confirmed by Dufour J, that the ovo-viviparous 

 insects are furnished with an abdominal pouch, in 

 which the eggs are deposited by the mother previous 

 to their being hatched. In this respect they afford a 

 striking analogy with the kangaroo, the opossum, 

 and other marsupial quadrupeds, which are furnished 

 with a similar pouch for protecting their young in 

 the first stage of their existence. One of our most 

 common flies exemplifies this. 



It may not have occurred to many of our readers 

 that there are more sorts than one of the large flies 

 usually called blow-flies and flesh-flies. One of these, 

 distinguished by its brilliant shining green colour and 

 black legs {Musca Ccssar, I^inn.), we have adverted 

 to§ in recounting the experiments of Redi ; another, 

 frequently called the blue-bottle {Musca vomitoria, 

 Linn.), is easily distinguished by the abdomen being 

 of a shining blue, the shoulders black, and the forehead 

 fox-coloured. The insect, however, to which we wish to 

 call attention at present, though nearly the size of the 



* Nouv. Diet. d'Hist. Nat. xxx. 426, 

 f Redi, Esperienze intorno alia Gen. degl' Insetii, 4lr«. 1668. 

 % Annales des Science? N;itiirclk'«. o Pa<:f» 3. 



