358 bklTlStt LEPIDOPTERA. 



appearance is shown pi. xvi., fig. 12 (x 7), representing the 6th 

 abdominal segment immediately after ecdysis. The areas are the 

 scars of the old tubercles, the dark central points are the rudimentary 

 tubercles of the 5th instar which still continue to bear minute hairs. 

 It is probable that many of these fall off later in the stage. The 

 explanation of the circular scar is as follows : The comparatively 

 light purplish or yellowish ground colour, alone present after ecdysis, 

 is subcuticular in position, being contained in the hypodermis cells. 

 This colour is not formed in the hypodermis cells which are 

 beneath the comparatively large shagreen-tubercles of the previous 

 stage. The dark colour, which subsequently appears, is cuti- 

 cular in position, and extends over the colourless hypodermis, 

 and thus conceals the great majority of the circular areas. Above 

 the subdorsal line the ground colour is at first purplish, the borders 

 to the stripes are also purplish, deepening into blue in the centre 

 of the darkest part, corresponding with the position of the red spot 

 in earlier stages [pi. xvi., fig. 12 (x 7) illustrating the arrangement 

 and tints of the ground colour, and the scars of the shagreen-dots, 

 as seen immediately after ecdysis, in the 6th abdominal segment]. 

 Below the subdorsal the ground colour is yellow or yellowish-green. 

 The thoracic legs are red, black at the tip. The horn is reddish- 

 orange at its base, yellow at the upper part and tip. The head is 

 yellow, but the parts which will become dark, are green. The 

 prothoracic plate is at first much swollen and green. Three ot 

 the chief tubercles are black and distinct on each side of each 

 abdominal segment (see fig. 12, in which two of these structures 

 are shown) ; the tubercles bear long and prominent hairs. This 

 examination of the larva immediately after ecdysis is evidently of 

 great importance, the stripes and borders bearing much resemblance 

 to those of the larva of Manduca (Acherontia) atropos in the last stage, 

 and, as hinted above, it gives the opportunity of describing the 

 colours due to pigment in the hypodermis cells, before everything 

 is concealed beneath the superficial pigment which is formed in 

 the cuticle. The larvae were compared on October 20th, when 

 they had apparently taken their permanent colour. There were, 

 nevertheless, some few modifications due to slight changes which 

 happened subsequently. The larvae examined were : 



1. Division I of the earlier stages (omitting the green variety of the 

 last stage). — Of the five larvae, three were dark like those last described, one of 

 them being even darker, and possessing no indication of the oblique stripes, 

 while the subdorsal was very slightly represented by a single spot on each segment. 

 (This larva is represented on pi. xvi., fig. 10.) The two other dark larvae pos- 

 sessed traces of the oblique stripes like the two larvae of division II. The two remaining 

 larvae were lighter varieties, one of them with the subdorsal distinct for its whole 

 length and expanded into a distinct spot at the anterior margin of each segment. 

 Above it was a dorsal line upon each side, similarly expanded into spots ; traces of 

 stripes were present. (This larva is represented on pi. xvi., fig. 7.) The 

 other larva only exhibited traces of the dorsal line and the subdorsal was less 

 distinct ; the stripes were similar. 



2. Division II of the early stages (omitting the green variety of the last 

 stage). — All three larvae were very dark, the ground colour being black ; the 

 subdorsal line was represented by a single spot on the anterior margin of each 

 segment, except anteriorly, where it was continuous ; the subspiracular line was 

 light and prominent. All three were very similar, except for slight differences 

 in the size and distinctness of the light subdorsal spots, and in the distance over 

 which the subdorsal formed a continuous stripe. There were very faint traces 



