Class Insecta 



523 



on the thorax. The forewings are tough and leathery and arise from 

 the dorsal part of the mesothorax. When folded back at rest, they 

 protect the broad thin hindwings of the metathorax. The hindwings 

 show many veins which originally arose as tracheae in early develop- 

 ment. Just dorsal to the second and third legs is a spiracle which ad- 

 mits air to the tracheae. 



HE*0— < THOBAX- 



!^t 



' OVIF»OStTOR. 



-TARSUS 



/PULVItLUS 



Fig. 173. — Lateral view of the grasshopper, Romalea sp. 



The abdomen is composed of eleven segments, each also consisting 

 of tergum, pleura, and sternum. The first segment bears on its lateral 

 surface the large tympanum for the reception of sound waves. A 

 series of eight pairs of spiracles are on the lower lateral portion of the 

 first eight abdominal segments. The posterior segments are modified 

 for reproduction. There is a dorsal, keeled anal plate covering the anus; 

 laterally there is a small triangular podical plate. Projecting between 

 the anterior ends of the podical plate and the anal plate on each side 

 is a small projection or cerciis. A'entrally the terminal segments are 

 different in the two sexes. In the male it is smooth and rounded, while 

 in the female two pairs of projections form the ovipositor for the depo- 

 sition of eggs. 



The Internal Anatomy of Romalea sp. — The digestive tract 

 is divided into distinct regions : the joregiit, viidgut, and hindgut. The 

 pharynx, the esophagus, the crop, and the provcntriculus constitute the 

 foregut ; the ventriculus and the gastric caeca are the midgut; and the 

 intestine, rectum, and anus are the hindgut. Ventral to the crop are a 



