MOTIONS OF INSECTS. 351 



They are however quite covered by irregular reticu- 

 lations, produced by various nervures sent forth by 

 the longitudinal ones, and running in all directions. 

 When at rest the inner part of one laps over that of 

 the other^: but in different genera there is a singular 

 variation in this circumstance. Thus in BlaKa, Phasmaj 

 and male Locustce, and generally speaking, but not in- 

 variably, in Gri/llus, F. and Tj^uxalis, — the left elytrum 

 laps over the right : but in Mantis, F. ; Maniispa, Latr. ; 

 some female Locustce ; Acheta ; and Gryllotalpa^ Latr., 

 the right is laid over the left. The wings in this order, 

 though always ample and larger than the tegmina, do 

 not invariably form a quadrant of a circle, falling often 

 short of it. They are extended by means of nervures, 

 which, like so many rays, diverge from the base of the 

 wing, and are intersected alternately by transverse 

 ones, which thus form quadrangular areas, arranged 

 like bricks in a wall. When at rest, they are longitu- 

 dinally folded. The flight of these insects, as far as it 

 has been observed, mucli resembles, it is said, that of 

 certain birds. Ray tells us that both sexes of the 

 house-cricket {Acheta domestica, F.) fly with an undu- 

 lating motion, like a woodpecker, alternately ascend- 

 ing with expanded wings, and descending with folded 

 ones''. The field- and mole-crickets {Acheta campestris 

 and Gn/llotalpa, F.), as we learn from Mr. White "^, — 

 and, since the structure of their wings is similar, pro- 

 bably tlie other Orthoptera — fly in the same way. 

 ■'■, llemipterous insects, with respect to their Hemelij- 

 ira, may be divided into two classes. Those in which 

 they are all of the same substance— varying from mem- 



' Pi-iTt X. Fig. g. " Uhl. Im. 63. " Afii. Hist. i\. 8:2. 



