8 HOW TO TEACH BEETLES, BUGS, AND LOCUSTS. 
feeler (maxillary palpus), and last of all the lower 
lip or labium also bearing a pair, of palpi. 
Any one who watches a grasshopper when feed¬ 
ing will be interested and amused. The maxillary 
and labial palpi help to pass the food inward between 
the mandibles which crush it. The most interest¬ 
ing thing about the mouth movements is the fact 
—uslwt 
LABIAL PALPI. 
_LABIUM. 
Fig. i.— Mouth-parts of Locust. 
that the mouth-parts move from right to left in¬ 
stead of up and down as in higher animals. 
But not all insects have their mouths composed 
of such curious parts. Such mouths are found 
only in insects which chew their food. But those 
whose food is liquid have no need of jaws and 
mandibles. Hence in these insects the mouth- 
