GRASSHOPPERS IN GENERAL. 



43 



third pair in walking and jumping. The function of tke third pair 

 differs, and yet the parts of each are the same, and these are given, 

 together with their relative forms, in figure 18. 



The wings differ in structure 

 and texture. The front wings (teg. 

 mina) are large, narrow, and retain the same form 

 whether in 'flight or at rest. The hind wings, 

 when not in use, are folded like fans and rest 

 under the tegmina. 



The membrane of the wings is supported by 

 longitudinal veins and short cross-veins. 



Abdomen. The first abdominal segment fits 

 accurately into a notch in the metasternum 



FIG. 19. (Original.) Dorsal aspect of body (female). A , head ; 

 1, antenna ; 2, epicranium ; 3, compound eye. B, nrothorax ; a, 

 preescutum ; 6, scutum ; c, scutellum ; d, post scutellum. C, mes- 

 onotum; sc, scutum ; 'scl, scutellum; w, tegmina or wing cover. 

 D, metanotum; sc, scutum; scl, scutellum; iv, wing. E, abdo- 

 men; 1, 2, 3, 4, 5. 6, 7, 8, 9, 10, 11, segments; auct, auditory organ; 

 *p, spiracles ; c, cerci ; pp, podical plates ; o, ovipositor. Enlarged 

 about three and a half times. 



( figs. 20, 21 ) . On the upper half of each side of 

 this first segment is a large opening covered with 

 a delicate membrane (figs. 21, 24). These are the 

 auditory organs. The membrane is the tym- 

 panum. In fig. 24 the auditory organ is enlarged. 

 The margin is the thickened tympanum. The dark structure at the 

 right on tympanum is the cone-shaped prominence which is situated 

 just beneath the tympanum. The dark spot near center is the trian- 

 gular chamber situated just beneath the tympanum. 



Just in front of each auditory organ is a spiracle (figs. 21, 24). The 

 next seven segments contain breathing spores (spiracles) on the 



