TYPICAL INSECTS 



185 



the abdominal segments. This jointedness is a character- 

 istic of all insects, and is extended also to the feelers, legs, 

 and mouth-parts. 



The grasshopper has six legs, composed of several stiff seg- 

 ments and a jointed foot terminated by minute forked claws 

 that act like pincers and are used for grasping. The legs of 

 insects are attached to the chest re- 

 gion, not to the abdomen, as some- 

 times seems to be the case. In the 

 grasshopper the first two pairs of 

 legs are not very strong, and are 

 used for crawling and holding to a 

 support. But the last pair are e& 

 pecially large and powerful, and are 

 used for making high and long 

 leaps. Observe how a locust uses 

 his legs. 



On the back of the thorax, from the second and third 

 segments, arise the two pairs of wings, which the grass- 

 hopper folds up like a fan when not in use. The first 

 pair are narrower and a trifle stiffer than the second, and 

 protect the last pair somewhat when folded. Unfold the 

 wings and examine them. Watch a grasshopper fly. In 

 flying the wings are extended at the sides and expanded. 

 The hind wings show bright colors in certain species. 

 Hold an expanded wing up to the light, and see that it has 

 a network of stiff ribs or veins running through the more 

 dehcate membrane. These act as a framework for the 

 wings. The veins of the wings of insects are differently 

 and characteristically arranged. Though grasshoppers 

 are generally seen to fly only short distances, they have 





Fig. 45. Part ol Compound Eye 

 of a Dragon-fly. 



(Photomicrograph 



