THE CUICKET O 



femur; the next segment is the tibia; and then comes a three- 

 jointed tarsus. These three divisions are found among in- 

 sects in generaL With fewer, the insect could hardly walk. 

 The wings are broad, flat outgrowths of the body- wall and, 

 like it, are covered by the cuticula. Between the two layers 

 of the cuticula are remnants of a space in which run the 

 air-tubes — these constitute the iving-veins, while the thin 

 parts of the wing enclosed by the veins are called wing-cells. 

 The arrangement of veins and cells in the different kinds of 

 insects, though following one plan, shows many modifications 

 in detail. In the cricket the upper wings are more leathery 

 than the lower, which, when not in use, are folded like a fan 

 under the protecting upper pair. The hind wings alone are 

 used in flight. The mechanism of flight is as follows. The 

 front edge of the wing is relatively stiff, while the hinder half 

 is loose and flops up when the -vving descends and down when 

 it ascends. Consequently in both up and down stroke the 

 wing meets a little resistance from behind and on the down 

 stroke from below as well, and this resistance behind is what 

 pushes the insect forward, while the resistance below keeps it 

 up in the air. Each stroke counts a little, and by making 

 many strokes a second even a heavy-bodied insect can propel 

 itself in the air. The cricket, however, is very bad at flight 

 and practically never uses its mngs for this purpose. 



Organs and Functions of Nutrition. — The mouth of the 

 cricket lies between and at the base of its heavy jaws. This 

 is the entrance to a digestive tube that runs through the middle 

 or axis of the body and has its other opening in the last ring of 

 the abdomen. As the food passes along this tube it is acted 

 on mechanically and chemically in different ways, and the 

 various parts of the tube show special regions each for its 



