THE COMMON RED-LEGGED GRASSHOPPER 



Hypopharynx 



unit of the eye does not make a complete image, but the 

 combined effect of all the units taken together produces a 

 mosaic pattern of whatever stands in range of the lenses. 

 In addition to the compound eyes, there are three ocelli 

 (Fig. 2), or simple eyes, 

 arranged, one almost Labrum 



in the exact center of 

 the front of the head, 

 and one directly above 

 the base of each an- 

 tenna. Notwithstand- 

 ing these two kinds of 

 eyes, it is doubtful 

 whether the grasshop- 

 per is able to perceive 

 well the outlines of ob- 

 jects or to distinguish 

 much except light and 

 movement. The ocelli 

 probably do not per- 

 ceive objects at a 

 greater distance than 

 a few inches, nor the 

 compound eyes at a 

 greater distance than 

 a few feet. 



The mouth of the 

 grasshopper is on the 



ventral, or lower, surface of the head. It is surrounded by 

 a number of structures, together known as the mouth parts 

 (Fig. 1). These consist of a flap-like upper lip, or labrum ; a 

 lower lip, or labium ; a pair of maxillse ; a pair of mandibles ; 

 and a tongue, or hypopharynx. The maxilla? are located at 

 the sides of the mouth. Both they and the labium have 



Maxillse 



^^W0 



Labium 



Fig. 1. Mouth parts of red-legged grass- 

 -. hopper, (x 4) 



