the Life History of Agriades escheri. 419 



hairs being white, and, as it happens, the yellow lateral 

 lines less marked than usual, although it has black hairs 

 along the dorsal flanges ; indeed, these hairs are so black 

 and conspicuous that they are probably the cause of the 

 rest of the hairs looking so white. 



The plant has been closely scrutinised several times a 

 day, yet this larva has escaped detection till now, several 

 of the preceding ones, of course, almost as successfully ; it 

 is probable that they come up the leaves very rarely, this 

 one perhaps never before. 



April 28th. — Found the ninth larva this morning high up 

 on a leaf. Since 24th the plant has been scrutinised a dozen 

 times without seeing a larva ; only one now remains un- 

 accounted for. 



The larva on entering last skin shows very white (really 

 colourless) lateral hairs, with sundry nearly black dorsal 

 ones, and the contrast is striking; later both sets of hairs 

 become of a rufous tint, as shown in Mr. Frohawk's 

 drawings. 



May 1st. — The larva is very similar to those of A. ther sites 

 and P. icarus; almost identical, in colouring, both as to 

 ground-colour, dorsal and lateral yellow lines, and oblique 

 markings on slope. It differs in the colours of the hairs. 

 The dorsal hairs are dark as in icarus (in thersites they are 

 white, except on thorax), but are if anything more conspicu- 

 ous. The lateral hairs are white at moult as in the two 

 other species, but become rufous or dark afterwards. Alto- 

 gether the larva is certainly much more like that of icarus 

 than that of thersites is to either of them. 



The remaining larvae were brought from the refrigerator 

 into a warm room on March 29th ; three moved the next day, 

 but they delayed eating, though not quite so long as the 

 first number, and none took the third moult till April 22nd. 



May 4th. — Of the last lot of larvae brought up all seem 

 now to be in 4th instar, the last one moulting to-day. They 

 hung fire very much before beginning to eat, and seemed 

 to eat more before moulting than the first lot did. Some 

 of them are very dark in colour, hardly any trace of green, 

 at any rate of the usual lively green, being present, and the 

 yellow stripes are hardly visible, but the dark band of mid- 

 slope is marked; others are light green with yellow flange 

 stripes, and have much the same facies as those in last 

 instar, but of course smaller. 



PL LXXXV shows the larva in last instar, two drawings 



