74 



INTERNAL STRUCTURE. 



pads, is noticed to swell. Presently the skin along this 

 swollen portion splits right along the middle of the head 

 and thorax, starting by a transverse, curved suture between 

 the eyes, and ending at the base of the abdomen. 



"Let us now imagine that we are watching one from the 

 moment of this splitting, and when it presents the appear- 

 ance of Fig. 43 a. As soon as the skin is split, the soft and 

 white fore-bod}^ and head swell and gradually extrude more 

 and more by a series of muscular contortions ; the new head 

 slowly emerges from the old skin, which, with its empty 

 eyes, is worked back beneath, and the new feelers and legs 

 are being drawn from their casings and the future wings 

 from their sheaths. At the end of six or seven minutes our 

 locust — no longer pupa and not 3^et imago — looks as in Fig. 

 43 b, the front four pupa-legs being generally detached and 

 the insect hanging by the hooks of the hind feet, which were 

 anchored while yet it had that command over them which it 

 has nowlost. The receeding skin is transparent and loosened, 

 especially from the extremities. In six or seven minutes 

 more of arduous labor — of swelling and contracting — witlr 

 an occasional brief respite, the antennae and the front four 

 legs are freed, and the fulled and crimped wings extricated. 

 The soft front legs rapidly stiffen, and, holding to its support 

 as well as may be with these, the nascent locust employs 



Fig. 43. — Molting: of a locust (Melanopolusspretus). — a, nymph ready to change; 

 b, the skin split along the back and the adult emerging; c, continues the process; 

 and at d, the adult insect drying out; e, perfect adult. After Riley. 



