PARTS OF THE MOUTH. 371 



lower one, is the lower lip., or labium. The upper 

 pair, of side-pieces, are called the mandibles, or 

 upper jaws ; the pair below are the lower jaws, 

 or maxilla. 



Let us now briefly mention the use of these 

 various parts of the insect's mouth ; beginning 

 with the upper lip, (a) or labrum. Unlike that 

 organ in ourselves, the insect's upper lip is gene- 

 rally, in such insects as bite their food, a plate of 

 horny substance, which serves the purpose of 

 an upper covering to the rest of the mouth. Like 

 our own upper lips, however, that is to say, like 

 those of men, at least, it is fringed with a sort of 

 moustache in most cases. 



The mandibles, (&) or upper jaws, in the biting 

 insects, are instruments for cutting the food 

 in pieces. When we bite our food, the move- 

 ment of our jaw is upwards and downwards ; but 

 in the insect it is like that of a pair of scissors, or 

 from side to side ! These jaws are sometimes 

 frightful-looking instruments, resembling, in the 

 stag-beetle, horns; and their power is proportion- 

 ally great. Although their general use is to mas- 

 ticate or crush the food for the insect, this apparatus 

 is often employed as a formidable weapon of 



