294 BRITISH BUTTERFLIES. 



attached to the foodplant by the cremastral hooks, by the cincture 

 round the waist, and a few strands of silk spun round it, forming a 

 slight cocoon (Frohawk). 



Maturation of pupa. — Directly after pupation, the chrysalis is 

 green, transparent, and one can still see the green dorsal line and the 

 segmental incisions ; the head is distinctly reddish ; the thorax is very 

 convex, and separated from the abdomen which is also strongly convex, 

 by a depression. The green tint slowly fades, and after some days 

 becomes pale yellow, whilst two days before the emergence of the imago, 

 the pupa becomes entirely black (Brabant). When freshly changed, 

 the colour of the pupa is of a clear transparent green, ;;: showing the 

 nervures of both the fore- and hindwings, and the general internal 

 structure ; it gradually assumes an ochreous tinge at both ends, and 

 the darker dorsal vessel can be seen pulsating as in the larva. When 

 four days old it is mostly of a dull ochreous-green ; the thorax whitish- 

 green, the head and anal segment pale pinkish-buff; the neuration of 

 both wings still showing. When nine days old, and mature, the colour 

 is of a pale ochreous-green ; the wings palest, inclining to whitish ; the 

 head, prothorax, and anal extremity, tinged with rust-red, caused by 

 the density of the reticulations and discs ; spiracles whitish ; nervures 

 still showing under the thin pupal skin. On the twelfth day the 

 maturing of the imago commences by the eyes becoming a pale reddish- 

 drab, and the wings opaque cream-colour ; the eyes daily deepen, and 

 wings become paler and more opaque. On the fifteenth day the eyes 

 are dark brown; the wings, thorax, and head light tawny-buff; the 

 abdomen greenish-ochreous. On the following day, the whole colour 

 is quickly transformed into black, blue, and grey. In the males the 

 wings are then rich deep metallic-blue at the base, blending into light 

 greenish-blue, forming the median area ; the rest of the wing black, 

 and black nervures crossing the blue ; outer border creamy-white ; the 

 eyes, thorax, and dorsal half of abdomen steel-black ; ventral surface 

 olive. A few hours before emerging, the blue of the wings assumes a 

 silvery-grey, and all the hair-scales of the body show clearly through 

 the thin delicate texture of the pupal skin, giving the whole a silvery- 

 grey appearance. 



Pupa. — The pupa looks naked, but there are a few hairs with 

 extremely fine speculations ; the hairs are about O06mm. or OOTmrn. 

 long. It is 10 - 4mm. long, 3-4mm. wide at wing-bases, 2mm. from 

 the front, and 4-2mm. at the 4th abdominal segment, 7mm. from the 

 front. The summit of the mesothorax (2-7mm. from front) is 3-5mm. 

 high, and after a waist at 4mm. from the front, the dorsum rises to 

 4-2mm. over the 2nd, 3rd, and 4th abdominal segments, just appreci- 

 ably highest over the 3rd abdominal. From the end of the wings, 

 7 , 7inm. from the front, the extremity is rounded, most on back, but 

 also slightly in front, the anal extremity being raised, not curved 

 ventrad, as in that of P. argus (aegon). The colour is green, pale, 

 with a, definite olive tint, and laterally and ventrally on the abdomen, 

 has a brownish tone as from overlying pink or purple. The dorsal 

 line is slightly darker, with a purple tone, and there is another line of the 



* Frohawk observes that, a larva which fed entirely on furze-blossoms after 

 hybernation remained :i much paler colour, being of a pale, greenish, yellow- 

 ochreous tint, whilst the pupa was likewise pale in colour. 



