LOCUSTS AND QRA88E0PPEBS. 93 



crust, which however is more or less flexible, but strong 

 enough (as seen in a beetle) to protect the soft parts 

 within from injury, and yet so light that the insect can hop, 

 run about, or fly, and not be impeded by its armor. 



We will begin our examination with the hind body, which consists 

 of ten rings, the tenth being imperfect. It will be seen that the first 

 nine rings are quite circular and well formed. At the end of the 

 hind body is the ovipositor. 



It wUl be seen that the legs are six in number, and that they are 

 attached to the chest or mid body in pairs, one to each segment. It 

 will be easy to separate the head from the first segment of the mid- 

 body or thorax, because it forms a large collar. If it be thus separated, 

 the legs will come off with it. This will leave the rest of the mid- 

 body composed of two segments, each bearing below a pair of legs, 

 and above a pair of wings. 



The chest or thorax, therefore, as seen in Fig. 97, consists of three 

 segments, called the "prothorax," "mesothorax," and " metathorax," 

 or fore, middle, and hind thoracic rings (see also Fig. .98). They 

 each bear a pair of legs, and the two hinder each a pair of wings. The 

 upper portion of the middle and hind segments, owing to the presence 

 of wings and the necessity of freedom of movement to the muscles of 

 flight, are divided or differentiated into two pieces, the "scutum" and 

 " scutellum" * (Fig. 97), the former being the larger, extending across 

 the back, and the scutellum a smaller, central, shield-like piece. 



It will be seen, also, that the side of each segment of the thorax is 

 divided into distinct pieces, so as to give freedom of motion to the 

 muscles of the legs and wings which are contained within the chest. 



The legs are each divided into a hip- joint (femur); a shank or tibia, 

 and a tarsus, or foot, with two toe- joints, ending in a pair of claws. 

 The thigh-joints, especially of the last pair, are much larger than the 

 others, as the locust is a vigorous leaper, hopping many times its own 

 height. The shanks are long and slender and armed with two rows of 

 spines. How the legs are attached to the chest may be seen by observ- 

 ing the specimen with the aid of the enlarged sketch (Figs. 98, 100, 

 and 101). 



The two pairs of wings are quite unlike; the front pair, when the lo- 

 cust is not flying, rests directly upon the hinder pair, but during flight 



* There are in some insects, as in many Lepidoptera and Hymenopt&ra 

 and the Newoptera, four tergal pieces, i.e., prasgautum, scutum, scu- 

 tellum, and postseutellum, the first and fourth pieces being usually very 

 small, and often imperfect. 



