THE GRASSHOPPER AND OTHER ORTHOPTERA 5 



folded up under the first pair. Both pairs of wings may 

 be regarded as folds of the general chitinous covering of 

 the body. Consequently they consist of a double chiti- 

 nous membrane. In certain places the chitin is thickened 

 to form the so-called veins which serve to give the wings 

 the degree of rigidity necessary for flight. 



The abdomen is composed of segments most of which are 

 similar in structure and freely movable upon one another. 

 The upper and lower parts of the segments are united 

 by a flexible membrane so as to permit a certain amount 

 of vertical movement between these parts. At the pos- 

 terior end of the abdomen is the opening of the intestine 

 and certain appendages used in reproduc- 

 tion. The end of the abdomen differs in 

 the two sexes and affords an easy means 

 of distinguishing the male from the female. 

 In the female the tip of the abdomen is fur- 

 nished with two pairs of acute processes 

 forming an organ called the ovipositor which FlG - 4- Part 



ofatrachealtube 



is used in laying the eggs in the ground, with coating of 



In the male the end of the abdomen is c 



blunt and swollen and is entirely devoid of an ovipositor. 



One of the most peculiar features of the grasshopper's 

 life is its mode of breathing. Watch the extension 

 and contraction of the abdomen and the changes in shape 

 of the segments. We might easily conjecture that these 

 movements had to do with breathing, but it is not so 

 apparent where air is taken into and expelled from the 

 body. With a hand lens, however, one may see a number 

 of small apertures called the spiracles along the sides of 

 the abdomen, and two larger pairs on the thorax. These 

 lead to the breathing tubes or tracheae which ramify through- 

 out the body and carry air to all the internal organs. 



The grasshopper also differs greatly from most animals 



