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 thence 

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

 ferent circumstances of temperature, do not sometimes 

 produce young, and at other times deposit eggs."f He 

 might as well, says R aumur, have asked whether, 

 in certain circumstances, a hen, instead of laying 

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

 contrary, has been ascertained by Rf aumur, 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 simi- 

 lar 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 Ccesar, LINN.), 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. 



t Redi, Esperienze intorno alia Gen. degP Insetti, 4to, 1668. 

 t Annales des Sciences Naturelles. Page 3. 



TOL. VI. 10 



