OVO-VIVirAROUS INSECTS. 



Ill 



and he computed that there were al)out 20,000 young 

 in the coil.* When this extraordinary fecundity is 

 considered, we need not wonder at the countless swarms 

 which appear as if by magic upon a jcint of meat du- 

 ring hot weather. 



Like most female insects, the mother-fly dies in a 

 few days after giving birth to her numerous brood; 

 but, unlike the oviparous flies, she seems to take a 

 considerable time to deposit the whole. It would be 

 impossible indeed for her pouch to contain the larvae 

 if they were all hatched at the same time; and there- 

 fore it has been so ordered by Providence that they 

 should arrive at maturity in succession. From the 

 early death of the mother, R aumur conjectured that 

 they did not scruple to eat their way through her 

 bowels; but he disproved his supposition by a most 

 decisive experiment. He took a fly wiiich had already 

 deposited a few larv.e, and closed the natural opening 

 of the pouch with sealing-wax, so that it was impossi- 

 ble any more could make their exit there. The mother 

 lived several days longer than she would have done, 

 had she been left at liberty to produce her young; but 

 not one of them attempted to force a passage, after 

 being shut up tor ten days. 



Another large gray fly withi)rick-red eyes (species 

 A 



A, large gray blow-fly, with the nhdonien opened, showing the young 

 maggols. B, breathing apparatus of the maggot of a large gray blow- 

 fly. 



Reaumur, INIeni. iv, 41' 



