32 THE BUTTERFLIES OF THE BRITISH ISLES. 



The Black- veined White (Aporia cratcegi). 



The Black- veined White (Plate 4) may be at once recog- 

 nized by its roundish white wings and their conspicuous veins, 

 which latter are black in the male butterfly, and in the female 

 brownish on the main ones (nervures) and black on the branches 

 (nervules). As the scales on the wings are denser in the male 

 than in the female, the former always appears to be the whiter 

 insect. On the outer margin of the fore wings there are more 

 or less triangular patches of dusky scales, and these in occasional 

 specimens are so large that their edges almost or quite meet, 

 and so form an irregular, dusky border to the fore wings. These 

 patches are also present on the hind wings, but are not so well 

 defined. Sometimes the patches are absent from all the wings. 

 The fringes of the wings are so short that they appear to be 

 wanting altogether. The early stages are figured on Plate 3. 



The egg is upright and ribbed from about the middle to the 

 curiously ornamented top, which appears to be furnished with 

 a sort of coronet. The colour is at first honey-yellow, then 

 darker yellow, and just before the caterpillar hatches, greyish. 

 The eggs are laid in a cluster on the upper side of a leaf of 

 sloe, hawthorn, or plum, etc., in the month of July. 



The caterpillar when full grown is tawny brown with paler 

 hairs arising from white warts ; the stripes along the sides and 

 back are black. The under parts are greyish. The head, 

 legs, and spiracles are blackish. Caterpillars hatch from the 

 egg in August, and then live together in a common habitation 

 which is formed of silk and whitish in colour. They come 

 out in the morning and again in the evening to feed, but a few 

 leaves are generally enclosed in their tenement. In October 

 they seem to retire for the winter and reappear in the spring. 

 During May they become full grown and then enter the 



