148 



BRITISH BUTTERFLIES. 



emits a small, short, and slender, white bristle ; 

 the lateral dilatation is glaucous-green, termi- 

 nating in a slender waved white stripe ; the 

 spiracles are very pale ; the ventral surface, 

 legs, and claspers are semi-transparent apple- 

 green; the minute points are present, but are 

 much fewer, and therefore do not communicate 

 the same dull colour to the ventral which is 

 observable on the dorsal surface. About the 

 18th of June the caterpillar lightly covers the 

 back of a leaf, or one of the twigs of its 

 food- plant with a carpet of extremely delicate 

 white silk, and to this it attaches itself by the 

 anal claspers, forming al-o a belt or loop, the 

 two extremities of which are firmly fixed, 

 close together, to the silken carpet at the 

 distance of a third of an inch from the anal 

 claspers; this loop passes over the back of 

 the caterpillar, supporting it equally well 

 whether on an erect twig or the horizontal 

 under surface of a leaf: this arrangement 

 being completed, the lateral plates of the 

 head separate, and the skin of the back is 

 partially ruptured, a green pointed protube- 

 rance making its appearance through the 

 aperture ; this green protuberance performs 

 a slow but constant circular gyration, and at 

 every gyration the skin of the caterpillar 

 recedes towards the anal extremity, leaving 

 more and more of the enclosed CHRYSALIS 

 exposed : when the moult is complete, the 

 shrivelled skin remains at the anal extremity. 

 The chrysalis is pointed at both extremities, 

 but has a dorsal thoracic hump, and a large, 

 bulging, rounded mass in front, which com- 

 prises the wing-cases ; it has also three ridges 

 one medio-dorsal, extend ing from the poin t ed 

 head to the anal extremity; the others lateral, 

 and bounding the dorsal area; these latter 

 are produced into an obtuse angle at the in- 

 sertion of the wing-cases, and at these angles 

 the diameter of the chrysalis is greatest, and 

 diminishes thence rapidly to the pointed head, 

 and gradually to the anal extremity ; the 

 lateral outline is, however, slightly incurved 

 behind the thorax ; the three ridges are very 

 inconspicuous. The colour of the chrysalis 

 is bright apple-green ; the head and thoracic 

 angles are tipped with purple-brown, this 



colour extending from the head towards the 

 thoracic hump, and from the thoracic angle 

 towards the tail ; the bulging mass contain- 

 ing the wing-cases is so transparent that the 

 outline of the body may be seen beneath it; the 

 dorsal ridge is darker than the ground colour, 

 forming a narrow, indistinct, smoke-coloured, 

 medio-dorsal stripe; the lateral ridge is paler 

 than the ground-colour, and forms a narrow, 

 rather indistinct, whitish stripe on each side 

 of the chrysalis. The chrysalis state lasts for 

 twenty days ; the earliest examples, those 

 from eggs laid on the 15th of April, may be 

 expected to appear on the wing on the 15th 

 of July. The sexes always keep apart during 

 the remainder of the year, never taking the 

 slightest notice of each other ; and both sexes 

 enter on a state of semi-bybernation very 

 early, but are frequently tempted abroad by 

 mild as well as sunny weather: in March 

 they reappear, and the usual attention of the 

 sexes* takes place, followed by the deposition 

 of eggs as already described : the butterfly 

 life of this species sometimes lasts for an 

 entire year, the faded butterflies of one year 

 actually surviving until those of the ensuing 

 year are on the wing; those, however, which 

 appear in spring, although tolerably perfect, 

 never have the exquisite freshness and beauty 

 which they possessed when disclosed in the 

 autumn ; and although individuals of two 

 consecutive years may often be seen together, 

 the eye of the experienced entomologist will 

 not fail to detect the difference. Newman. 



TIME OF APPEARANCE. Caterpillar in May 

 and June; chrysalis in July; butterfly chiefly 

 in July and August, but to be seen every 

 month in the year. 



Obs. All the English students of ento- 

 mology commence their career by considering 

 the vernal hybernated individuals of the 

 Brimstone to be the descendants of the au- 

 tumnal ones : this very pardonable mistake 

 was discussed at great length in the " Zoolo- 

 gist" for 1855 and 1856. 



LOCALITIES. Woods, lanes, and gardens. 

 M r. Birchall says that it occurs at Killarney, 

 but is apparently confined to the south of 

 Ireland ; and the Hon. Emily Lawless 



