Natural History and Transformations. 79 



[Fig. 11.] 



to a meridian ridge, and in lacking wings, the young 

 locust scarcely differs in structure from its parent ; and 

 the perfect, winged form is gradually assumed through a 

 series of five molts, during the first four of which the 

 wing-pads become larger, 

 and during the last, from 

 the pupa (Fig. 11, c), to 

 the perfect state, the tho. 

 rax becomes flattened, the 

 wings are acquired, and the 

 insect ceases to grow and 

 is ready to procreate. The 



Rocky Mountain Locust: -a, a, newly 

 time required from hatching hatched larvae ; &, full-grown larva ; c, pupa. 



till the wings are obtained, differs very much according to 

 latitude and season, but averages from six weeks to two 

 months. 



In order to illustrate the interesting process of molting 

 we will trace an individual through the last molt — from 

 the pupa to the winged insect — as it is the most difficult, 

 and, on account of the larger size of the animal, most 

 easily watched. The other molts are very similar, except 

 that the wing-pads increase but moderately in size with 

 each. When about to acquire wings the pupa crawls up 

 some post, weed, grass-stalk, or other object, and clutches 

 such object securely with the hind feet, which are drawn 

 up under the body. In doing so the favorite position is 

 with the head downward, though this is by no means essen- 

 tial. Remaining motionless in this position for several 

 hours, with antennae drawn down over the face, and the 

 whole aspect betokening helplessness, the thorax, especially 

 between the wing-pads, is noticed to swell. Presently the 

 skin along this swollen portion splits right along the mid- 

 dle of the head and thorax, starting by a transverse-curved 

 suture between the eyes, and ending at the base of the 



