68 BEGINNERS' ZOOLOGY 



the grasshopper's range of vision compare with that of the 

 crayfish ? 



Are the antennae flexible ? What is their shape? Posi- 

 tion ? Are they segmented ? Touch an antenna, a wing, 

 a leg, and the abdomen in succession. Which seems to be 

 the most sensitive to touch? The antennae 

 are for feeling. In some species of insects 

 they also are organs of hearing and smelling. 

 The mouth parts of a grasshopper should 

 be compared with the mouth parts of a bee- 

 tle shown in Fig. 113, since they correspond 

 Fig. 113. closely. If the grasshopper is fed with a 

 blade of fresh grass, the function of each organ may be 

 plainly seen. It is almost impossible to understand these 

 functions by studying a dead specimen, but a fresh speci- 

 men is much better than a dry one. 



The upper lip, or labn/w, is seen in front. Is it tapering 

 or expanded ? In what direction is it movable? The dark 

 pointed biting jaws {mandibles) are next. Are they curved 



Fig. 114. — a, Food Tube of Beetle. 



6, gizzard ; d, intestine; c, biliary vessels. See Fig. 127. 



or straight ? Sharp or blunt pointed ? Notched or smooth ? 

 Do they work up and down, or sideways? The holding jaws 

 {maxillce), each with two jaw fingers {maxillary palpi), are 

 behind the chewing jaws. Why? The lower lip {labiuvi) 

 has a pair of lip fingers {labial palpi) upon it. The brown 



