THE PEARL-BORDERED FRITILLARY. 95 



Variation on the upper side consists of more or less black 

 suffusion on the basal or general area of the wings, and an in- 

 crease in the size of the black spots, resulting in the formation of 

 bands or patches ; or the black spots may be much reduced in 

 size, and some of them entirely absent. Some of the more 

 striking kinds of aberration, both above and below, are repre- 

 sented on Plate 56, Figs. 1-3, and Plate 65, Figs. 1-4. The usual 

 colour is sometimes replaced by buff, and this may be yellowish 

 or whitish in tint ; occasionally white spots appear on the 

 wings. The life-history of this butterfly is depicted on Plate 60. 



The egg, which is laid in May or June, is whitish-green at 

 first, and afterwards turns brownish. It is distinctly ribbed, 

 and the top is somewhat rounded and hollowed in the centre. 



The full-grown caterpillar is black, and the numerous minute 

 hairs with which it is clothed give it a velvety appearance. 

 There is a greyish-edged black line down the middle of the 

 back, and the spines on each side of this are whitish or yellowish, 

 with the tips and the branches black ; all the other spines are 

 black. A greyish stripe runs along the lower part of the sides, 

 and this is traversed from the fourth to the last ring by a 

 blackish line. Head black, shining, downy, and slightly notched 

 on the crown. The natural food-plant is dog-violet ( Viola 

 canina), but the caterpillar will also eat garden pansy, and has 

 been known to nibble a leaf of primrose. It retires for hiberna- 

 tion when quite small, and recommences to feed in March. 



The chrysalis is brownish, with the raised parts of the thorax 

 and head greyish ; the body is paler brown, and the points 

 thereon are blackish. 



This butterfly seems to be fairly common in woods through- 

 out England and Wales, and it is often abundant in some of the 

 more extensive woodlands, especially in the southern counties. 

 It used to be plentiful in Northumberland and Durham, but has 

 become scarcer in those counties, and in some others in the 

 north of England. It occurs in Scotland, and is not uncommon 



