MOTIONS OF INSECTS. 271 



of muscles attached to the skin, that take their origin 

 within the body*. 



I shall begin the list of isoalkerSy the movements of 

 which are aided by various instruments, with one which 

 is well known to most people, — the grub of the nut- 

 weevil {Balajiinus Nucum). When placed upon a table, 

 after lying some time, perhaps, bent in a bow, with its 

 head touching its tail, at last it begins to move, which, 

 though in no certain direction, it does with more speed 

 than might be expected. Rcisel fancied that this animal 

 had feet furnished with claws ; but in this, as De Geer 

 justly observes, he was altogether mistaken, since it has 

 not the least rudiment of them, its motion being pro- 

 duced solely by the alternate contraction and extension 

 of the segments of the body, assisted, perhaps, by the 

 fleshy prominences of its sides. — Other larvae have this 

 annular motion aided by a slimy secretion, which gives 

 them further hold upon the plane on which they are 

 moving, and supplies in some degree the place of legs 

 or claws. That of the weevil of the common fisrwort 

 [Clonus Scrophularicc) is always covered with slime, 

 which enables it, — though it renders its appearance dis- 

 gusting, — to walk with steadiness, by the mere length- 

 ening and shortening of its segments, upon the leaves 

 of that plant''. — Of this kind also are those larvae, 

 mentioned above<=, received by De Geer from M. Zier- 

 vogel, which, adhering to each other by a slimy secre- 

 tion, glide along so slowly upon the ground as to be a 

 quarter of an hour in going the breadth of the hand, 

 whence the natives call their bands Gards-drac' ^. 



' Ciivier, Anat. Covtp. i. 4.30. *■ De Geer, v. 210. 



° See above, p. 7. J De Geer, vi, 338. 



