30 SPHINGID.E. 



undulatory motion of the body, and the prolegs and claspers 

 gradually lose their prehensile power. Some species burrow 

 into the ground and form an oval cell (Acherontiin^: and 

 Ambultcin^:), others (most of the Philampelinje and ail the 

 Chgeeocampin^e) make a rough cocoon of leaves and rubbish, 

 held together with strands of silk, on or very near the surface 

 of the ground, sometimes even on the food-plant itself. Some 

 of the burrowing species dig as deep as 6 inches in suitable 

 soil ; they make an ovoid cell, smoothing the inside apparently 

 by pressing with the head, and some species coat the walls 

 with silk. After a period, which is normally about a week 

 or ten days but may extend to months, the larval skin 

 splits along the dorsal line of the head and along one side of 

 the clypeus to the end of the third segment of the body, and 

 is forced backwards by the alternate inflation and contraction 

 of the body. When the pupal cell is lined with silk or pupation 

 takes place in a cocoon, the larva spins a pad of silk at one 

 end and this pad is gripped by the claspers before pupa- 

 tion. When the pupa is nearly free of the larval skin, it 

 thrusts out the anal segment bearing the cremaster and fixes 

 the hooks of the cremaster into the pad of silk by a screwing 

 motion of the abdomen which also completely displaces the 

 larval skin. The larval head- case remains attached to the 

 skin with the two lobes separated and the clypeus, labrum 

 and ligula in one piece. In some genera, such as Clanis, 

 Leucophlebia and Clanidcypsis , the larva does not pupate 

 for a long time after burying itself, but retains its larval 

 skin for a period which may extend into months. It then 

 pupates, and the moth emerges after two or three weeks. 



When the pupa first breaks through the larval skin it is 

 green in colour, soft and plastic, and nearly as long as the 

 larva was before pupation. The tongue, antennae, legs 

 and wings, or, rather, the cases in which these organs will 

 be formed, are at first separate from the body, but very 

 quickly settle into their appointed places and become fused 

 together. The abdomen shrinks considerably in length as 

 the membranes between the segments contract, and in about 

 an hour's time the pupal case has assumed its final form, 

 the surface has hardened and the green colour has changed 

 to the final coloration. The pupa lies quiescent, and the main 

 bulk of the tissue undergoes degeneration into a liquid fatty 

 substance from which the moth takes form. In some cases the 

 moth emerges in as short a period as fourteen days, but the 

 period may extend to several months, or even years. Before 

 the moth emerges the pupal case becomes fragile, thinning 

 in some way from the inside as the moth develops. The pupal 

 case splits, in much the same way as the skin of the larva 

 splits in its final moult, down the dorsal line of segments 2 to 4. 



