5° 



FIRST LESSONS IN ZOOLOGY 



Note tliat almost tlie whole outer surface of the body is 

 co\ercd with a firm, smooth coat, the chitinized cuticle, 

 that is, the horny outer layer of the skin. The skin 

 of the neck, however, and that at the bases of the \e<^^ 

 and wini;s is soft. Why is this necessary .'' What is the 

 most obvious use of this hard outer covering^.'' Note that 

 the soft skin of the neck is well protected by the projectin^r 



antenna; 



■oinpositor 



■iir^iil se(/nie'iiti; 



Flc. 29.- -L(lCll^t Willi extern, il ]i:irts iiamecj. 



saddle-sliajjed liorti}' piece on the front thoracic body- 

 rinfj. Anotlier use of the firm cuticle, or c.vo-skeleton, 

 as it is called, is to afford solid points of attachment for 

 the many muscles of the body, the locust having- no 

 bones or any kind of internal skeleton. (In a few places 

 there are processes or continuations of the c.x'o-skeleton 

 I)rojectini.^f internally.) 



That part of the body behind the thora.v is called the 

 abdomen. l^L.xamine the upper side of the first (nearest 

 the thorax) Vjody-rin!_;' of the .abdomen, and fmd two 

 small, nearly circular, thin places lookinj^r Ij]<e little 

 v\indows. These are the hearing organs, or tympana, of 



