96 



BUCCAL APPARATUS OF INSECTS. 



with a central piece, named labrum, or upper lip (a, Figs. 

 414 and 415); and has on each side a kind of large tooth, 

 moveable and very hard, called the mandible, or upper jaw (6), 

 which serves to divide the food. Immediately behind these 

 mandibles is found a second pair of appendages, whose structur^ 

 is very complicated ; these are the second pair of jaws, termed 

 the maxillce (c). Each of these last organs has on the inside a 

 plate or cylinder, of greater or less hardness, generally armed 

 with notches or hairs, and on the outside one or two small ap- 

 pendages composed of several joints, and termed maxillary palpi. 

 Behind the maxillae is found another pair of appendages usually 

 united to form a single organ, supported upon a central piece, 

 the mentum, or chin. These form the labium or lower lip, 

 (Fig. 415, d) ; they close the mouth from beneath, and are ap- 

 plied against the maxillae, as those organs are themselves applied 

 against the mandibles. The labium usually bears a second pair 



Mandible _ 



Maxillary Palp 



Lateral Lobes of 

 the Tongue 



-- Tongue 



FIG. 417. HEAD OF 

 ANTHOPHORA. 



FIG. 418. PARTS OF THE MOUTH 

 SEPARATED. 



of jointed appendages, or palpi, which are called labial palpi. 

 The form of the various parts varies greatly according to the 

 nature of the food. The palpi serve principally as organs of 

 touch ; the mandibles are employed in the division of the food, 



