58 



COMPARATIVE ZOOLOGY. 



Fio. 21.— Mouth of fi Lncnst dissected: 1, labrum, or upper lip; 2, mimdiblen ; 3, 

 jiiws; 4, labium, or lower lip; 5, tougue. Tlie appeiida^e^s to the maxilise aud 

 lower lip are palpi. 



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

 oral apparatus consists of two pairs of horny jaws {mandi- 

 bles and maxillce), which work horizontally between an 

 upper {labrum) and an under {labium) lip. The maxillae 

 and undet lip carry sensitive jointed feelers {palpi). The 

 f I'ont edge of the labium is commonly known as the tongue 

 {ligula)."^ In such a month, 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 



