PACKAuu.] HABITS OF THE YOUNG LOCUST. 631 



each molt the wings, at first very small, increase in size. Mr. Riley de- 

 scribes minutely the molt of the pupa into the fully-winged state. 



When about to acquire wings the pupa crawls up some post, weed, 

 grass-stalk, or other object, and clutches such object securely by the 

 hind feet, which are drawn up under the body. In doing so the fav- 

 orite position is with the head downward, though this is by no means 

 essential. Eemaining motionless for several hours in this position, 

 with autennte drawn down over the face, and the whole aspect betoken- 

 ing helplessness, the thorax, especially between the vriugpads, 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 w^e are watching one from the moment of this 

 splitting, and when it presents the appearance of Fig. 4, a, Plate LXII. 

 As soon as the skin is split the soft and white fore-body and head swell 

 and gradually 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. 4, 6, the four front pupa-legs being generally de- 

 tached, 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, espe- 

 cially from the extremities. In six or seven minutes more of arduous 

 labor, of swelling and contracting, with .an occasional brief respite, the 

 auteunse 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 well as may be with these, the nascent locust employs what- 

 ever muscular force it is capable of to draw out the end of the abdomen 

 and its long hind legs (Fig. 4, c). This in a few more minutes ic 

 finally does, and, with gait as unsteady as that of a new-dropped colt, 

 it turns round and clambers up by the side of the shrunken cast-off skin 

 and there rests, while the wings expand and every part of the body 

 hardens and gains strength, the crooked limbs straightening and the 

 wings unfolding and expanding like the petals of some pale flower. 

 The front wqngs are at first rolled longitudinally to a point, and as 

 they expand and unroll, the hind wings, which are tucked and gathered 

 along the veins at first, curl over them. In ten or fifteen minutes from 

 the time of extrication these wings are fully expanded and hang down 

 like dampened rags (Fig. 4, d). From this point on, the broad hind wings 

 begin to fold up like fans beneath the narrower front ones, and in another 

 ten minutes they have assumed the normal attitude of rest. Meanwhile 

 the pale colors which always belong to the insect while molting have 

 been gradually giving way to the natural tints, and at this stage our 

 new-fledged locust presents an aspect fresh and bright. (Fig. 4, e.) If 

 now we examine the cast-off skin, we shall find every part entire, with 

 the exception of the rupture which originally took place on the back, 

 and it would i)uzzle one who had not witnessed the operation to divine 

 how the now stiflhind shanks of the mature insect had been extricated 

 from the bent skeleton left behind. They are in fact drawn over the 

 bent knee joint, so that during the process they have been bent double 

 throughout their length. They were as supple at the time as an oil- 

 soaked string, and for some time after extrication they show the efl'ects 

 of this severe bending by their curved appearence. 



The molting, from the bursting of the pupa-skin to the full adjustment 



