MOTIONS OF INSECTS. 2S1 



on its back, you would immediately conclude that he 

 was playing upon your credulity, and had lost that re- 

 gard to truth which ought to distinguish the narratives 

 of persons of his description. What then will you say 

 to me, when I affirm, upon the evidence of two most 

 unexceptionable witnesses, Reaumur and De Geer, 

 that there are insects which exhibit this extraordinary 

 structure ? The grub of a little gall-fly, appearing to 

 be Cynips Quercus inferus of Linne — which inhabits a 

 ligneous gall resembling a berry to be met with on the 

 underside of oak-leaves — was found by the former to 

 have on its back, on the middle of each segment, a re- 

 tractile fleshy protuberance that resembled strikingly 

 the spurious legs of some caterpillars. A little atten- 

 tion will convince any one, argues Reaumur, that the 

 legs of insects circumstanced like the one under consi- 

 deration, if it has any, should be on its back. For this 

 grub — inhabiting a spherical cavity, in vvhich it lies 

 rolled up as it were in a ring — when it wants to move, 

 will be enabled to do so, in this hollow sphere, with 

 much more facility, by means of legs on the middle of 

 its back, than if they were in their ordinary situation^. 

 So wisely has Providence ordered every thing. — An- 

 other similar instance is recorded by De Geer, which 

 indeed had previously been noticed, though cursorily, 

 by the illustrious Frenchman''. There is a little larva, 

 he observes, to be found at all seasons of the year, the 

 depth of winter excepted, in stagnant waters, which 

 keeps its body always doubled as it were in two, against 



^ Reaum. iii. 496. t. xlv. /. 3. 



" Ibid. Mem. de VAcad. Roy. des Scien. dc Paris, An. niJ. p. 203. 



