CLASS INSECTS. 879 



reunited to the languette. These different parts vary accord- 



Fig. 355. Head of the Blatta, 

 viewed before.* 



Fig. 356. Buccal Appendages 

 oftheCarabus. 



ing to the nature and consistence of the food. The palpi serve 

 principally to seize the food 

 and to hold it between the 

 mandibles whilst they di- 

 vide it. Sometimes the 

 jaws assume an enormous 

 development, forming a 

 sort of forceps in front of 

 the head ; ' this arrange- 

 ment is very remarkable 

 in the heron beetle (Fig. 

 357), and in the other spe- 

 cies of the genus lucanus, 

 522. For sucking in- 

 struments the jaws and 

 the labium become elon- 

 gated, so as to form a 

 kind of tubular proboscis, 

 in the interior of which 

 there are often delicate 

 filaments, performing the 

 functions of little lancets, 

 and formed of the man- 

 dible and jaws, extremely 

 modified. 



Fig. 357. Lucanus Metallicus. 



* a, antennae ; b, compound eyes ; c, single eyes ; d, labium ; e, man- 

 dibles ; /, jaws ; g, little tongue ; h, labial palpi. 



