80 



abdcmen. Let us now imagine that we are watching one 

 from the moment of this splitting, and when it presents 

 the appearance of Fig. 12, a. As soon as the skin is split, 

 the soft and white fore-body and head swell and gradually 



[Fig. 12.] 



Rocky Mountain Locust :— Process of acquiring wings • a, pupa with skin just 

 split on the back ; 6, the imago extruding ; c, the imago nearly out ; d, the imago with 

 wings expanded. 



extrude more and more by a series of muscular contor- 

 tions ; the new head slowly emerges from the old skin, 

 which, with its empty eyes, is worked back beneath ; 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 

 yet imago — looks as in Fig. 12, 5, the four front 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 now lost. The 

 receding skin is transparent and loosened, especially from 

 the extremities. In six or seven minutes more of arduous 

 labor — of swelling and contracting — with an occasional 

 brief respite, the antennae and the four front legs are freed, 

 and the fulled and crimped wings extricated. The soft 

 front legs rapidly stiffen, and, holding to its support as 



