96 



BUCCAL APPARATUS OF INSECTS. 



lary palpi. Again, behind the maxillae is found a second pair of 

 appendages, whose base is supported by a central piece, called 

 the mentum, or chin. These appendages constitute the tongue 

 (d, Fig. 314) ; they are applied against the maxillae, as these 

 organs are themselves applied against the mandibles. We have 

 further to mention a second pair of jointed moveable appendages, 

 or palpi ; which are termed labial palpi, the name of labium, 

 or lower lip, being commonly given to the piece formed by the 

 union of the tongue and mentum (d. Fig. 315). The form of 

 these various parts differs according to the nature and consist- 

 ency of the food. The palpi serve principally for seizing the 

 food, and holding it between the mandibles whilst these divide 

 it. Sometimes the maxillae have an enormous development, and 

 form a large pair of pincers on the front of the head ; an arrange- 

 ment which is very remarkable among the Stag-beetles, and 

 other species of the genus Lucanus (Fig. 316). 



614. Amongst the sucking Insects, the maxillse or the labrum 

 are lengthened, so as to constitute a tubular trunk ; in the 



Mandible 



Maxillary Palp 



Maxilla 



Labial Palp 



Lateral Lobes of 

 the Tongue 



FIG. 317- HEAD OF 



ANTHOPHORA. 



FIG. 318. PARTS OF THE MOUTH 

 SEPARATED. 



interior of which we frequently find delicate filaments, perform- 

 ing the functions of small lancets, and formed by the mandibles 

 and maxillse modified to such a degree as to be hardly percep- 



