INTERNAL ANATOMY OF INSECTS. 87 



all his attention could perceive no motion in it a . Reau- 

 mur also fancied he perceived in the grub of Musca 

 vomitoria, in which he in vain looked for the dorsal ves- 

 sel, a fleshy part which exhibited alternate pulsations ; 

 and when with a pair of scissors he made a lateral in- 

 cision in the insect, amongst other parts that came out, 

 there was one that had movements of contraction and 

 dilatation for several minutes, this experiment was re- 

 peated with the same result upon several grubs b . De 

 Geer, whose love of truth and accuracy no one will call 

 in question, saw the appearance of blood-vessels in the 

 leg of the larva of a Phryganea L. (as Lyonet did in 

 those of a flea c ) ; and in the transparent thigh of Ornt- 

 thomia amcularia he discovered a pulse like that of an 

 artery d . Baker, whose only object was to record what 

 he saw, speaks of the current of the blood being remark- 

 ably visible in the legs of some small bugs e : what he 

 meant by that term is uncertain, but they could not be 

 spiders, which he had just distinguished. This author 

 has likewise seen a green fluid passing through the ves- 

 sels of the wings of grasshoppers f ; and M. Chabrieris 

 of opinion that insects possess the power of propelling a 

 fluid into the nervures of their wings and withdrawing it 

 at pleasure, as they are elevated or depressed * ; but this 

 last fact may be independent of a circulation. 



But though these arguments, which I have stated in 

 their full force, appear strong, and at first sight conclu- 



a Bonnet ii. 309. Perhaps in both cases the alimentary canal was 

 the organ seen. 



b Reaum. iv. 171. c Lesser L. ii. 84. note. 



55 De Geer ii. 505. vi. 287. r On the Microscope, i. 130. 



f Ibid. E Sur le Vol dcs Ins. 325. 



