NOTES ON CHARAXES JASIUS. 219 



Additional slight folds of effete skin occur across the dorsum of the ab- 

 dominal segments. The third stage, if not of greater activity, at least 

 of very much more rapid progress, is entered upon. The skin of the 

 abdominal dorsum slides • backwards, and accumulates at the anal 

 extremity, ventrally, the suspensory processes of the pupa, which are 

 very large and conspicuous in this pupa, are easily seen through the 

 delicate skin to hook into a fold of the skin of the last segment, or 

 rather into the fold formed by the incision with the next segment, 

 and the skin of the ventral surface accumulates in front of this. It 

 is also tolerably evident, though the folds of larval skin are now thick 

 enough to rather obscure it, that the cremastral process is thrown 

 backwards at each vermicular movement, acting from the suspensory 

 processes as centres of rotation, so as to push the successive folds of 

 dorsal skin, as formed, down between it and the suspensory processes. 

 The succession, or rather concurrence, of events is now very rapid ; 

 one notes the white points formed at the spiracles by the dragging 

 out of tracheal linings, quickly extending into a continuous line, and 

 one notes especially such a lining drawn out between the 2nd and 

 3rd thoracic segments, where the imago has, but the larva has not, a 

 spiracle. Suddenly one sees that the larval skin is ruptured down 

 the centre of the thorax, and soon that the head is split in half, with 

 the clypeus in a separate piece, which follows the mouth parts. 

 Quickly the Skin passes towards the tail, the cremaster has pushed all 

 the dorsal skin below it and appears, through the dorsal slit, and at the 

 second push through, it seizes the pad of silk, and then the movements 

 of the pupa push it oft" the suspensory processes, and, all weight being 

 taken off it, and receiving some upward pushes, the crochets of the 

 anal pro-legs also are loosened from the pad of silk, and the skin is 

 free and falls. This pupa, chiefly perhaps from its large size, but also 

 from the colouring of the suspensory processes, renders the part the 

 latter play in thejcasting of the larval skin, very easy to observe, a func- 

 tion which was very carefully demonstrated a number of years ago 

 by Dr. Osborne. The casting of a tracheal lining from the 2nd 

 thoracic spiracle at pupation I do not remember to have observed 

 before, but inferred that such occurred, since I had seen it many 

 years ago in numerous larval moul tings ; first in the large silkworms 

 [Antheraca yama-mai, L.), and had also demonstrated the existence of 

 this spiracle in the imagines. The pupa is still of considerable 

 length, and comparatively narrow, and the wings and appendages are 

 short, only reaching to the middle of the 3rd abdominal segment ; 

 all the abdominal segments also are rounded with deep incisions. 

 Vermicular movement continues, with the result of gradually bring- 

 ing the pupa into its short, squat form, with very dwindled terminal seg- 

 ments. During this process the wings and appendages nearly double 

 in length, and the vermicular movements seem to cause this result 

 by a process of forcing the fluids from the diminishing to the increas- 

 ing parts. It was during this stage that I noticed the phenomenon 

 that I have alluded to as entirely new to me. At the commencement 

 of this stage the spiracles (abdominal) are wide, oval depressions, 

 with apparently the spiracle proper of a brownish colour at the bottom, 

 and during the process they become narrower, till they are, in the 

 mature pupa, very narrow lines, with questionably any actual lumen. 

 I did not catch this detail immediately, but within a minute or two 



