TERHESTlilAL LARV.E. 279 



annular segments of the body are moved, are ex- 

 ceedingly numerous, and beautifully arranged with 

 reference to the motions they are intended to effect. 

 The investigation of the structure of these minute 

 organs has long exercised the talents of the most 

 skilful entomologists, and still oft'ers much that 

 remains to be explored. The researches of Lyonet, 

 already alluded to, on the anatomy of the larva of 

 the Bombyx Cossus* of which he has published an 

 elaborate description, accompanied by admirable 

 engravings, will ever remain a splendid monument 

 of patience and ingenuity in overcoming the diffi- 

 culties which impede this kind of inquiry. In the 

 body and the limbs of this caterpillar, Lyonet 

 counted above 4000 separate muscular bands, all 

 arranged with the most perfect symmetry, and 

 adapted with wonderful precision to the perform- 

 ance of the required effects. 



In these larvse, as in the simpler forms of the 

 Annelida, progression is often accomplished solely 

 by the alternate contraction and extension of the 

 annular segments, aided, in many cases, by short 

 hairs, and frequently, also, by a slimy secretion 

 which exudes from their bodies. Many larvae 

 which are destitute of feet, move onwards by first 

 coiling the body into a circle, making the head 

 and the tail meet, and then springing forwards by 

 a sudden extension of the back, producing an effect 

 like the unbending of a bow. By an artifice of the 

 same kind, some larvae, unfolding with a violent 

 effort the curvatures of their bodies, contrive to leap 

 to considerable distances. 



* Cossus liyniperda, Fabricius. 



