THE CUICKET 6 



Which side is right, which left, and why? Such are tlie ques- 

 tions which attention to a living cricket will readily answer. 

 They are important because these surfaces and sides and 

 ends are essentially similar even in such vmrelated animals 

 as the cricket and cat, which have this in common that they 

 move over the ground. 



The External Structure of the Cricket (Figs. 3 and 4). — 

 The cricket's exterior (Uffers from ours in being covered with 

 a thick varnish-like layer called the cuticula. This cuticula 

 is the cricket's skeleton, for it supports the body and gives 

 attachment to the muscles of the legs. The cuticula extends 

 over the mouth parts and even into the mouth. It cannot 



]?IG. .3. — Side view of female criflcet, with legs and wings removed. 



stretch and so, in order to let the animal grow, the cuticula 

 bursts from time to time and is shed. The cricket's body is 

 made up of a trunk and appendages. The trunk consists of 

 a series of rings, or somites (Fig. 4), which are grouped into 

 three main regions known as head, thorax, and abdomen. The 

 rings are most clearly seen on the abdomen, where each bears, 

 on the two sides, a pair of small holes that are the entrance 

 to the system of air-tubes of the cricket and are known as 

 spiracles. The thorax is made up of three somites, each of 

 which bears a pair of legs, and two of them each a pair of 

 wings. On the head the somites are blended, but the origi- 

 nal number can he made out by applying the rule that each 

 somite carries a pair of appendages. There are one pair 



