58 



COMPARATIVE ZOOLOGY. 



PIG. 21 Mouth of a Locust dissected: 1, labrnm, or upper lip; 2, mandibles; 3, 

 jaws; 4, labinm, or lower lip; 5, tongue. The appendages to the maxillae and 

 lower lip are palpi. 



the suctorial (as the Butterfly). In the former group, the 

 oral apparatus consists of two pairs of horny jaws (inandi- 

 bles and maxillce), which work horizontally between an 

 upper (Idbrum) and an under (labium) lip. The maxillae 

 and under lip carry sensitive jointed feelers (palpi). The 

 front edge of the labium is commonly known as the tongue 

 (ligula)? 1 In such a mouth, the mandibles are the most 

 important parts; but in passing to the suctorial Insects, 

 we find that the mandibles are secondary to the maxillae 

 and labium, which are the only means of taking food. In 



