26 [February, 



crepis for a few days appeared to have very pale coloration. It was 

 then too late for any success in testing whether this was a result of the 

 change of food, or merely of an accidental selection of pale larva? to 

 place on this plant. 



These larva? of argyrogn&mon, 10-13 mm. long (PI. I, figs. 1, 2, 

 3, 4, 6, x nearly 3) , presented very great variety m colour and intensity 

 of marking ; numerous as they were, one might almost say no two were 

 alike. The commonest form, i.e., the one in which a large number 

 nearly agreed, was a green larva with a dark brown dorsal band, much 

 the broadest in front, edged with white and a white lateral line, rather 

 darker spiracles, a few black dorsal and pale lateral hairs, and the rest 

 of the skin closely studded with points (hair bases) , black dorsally and 

 white laterally. Figs. 2 and 4 would be examples in this group, some 

 of which had a little more marking ; some were nearer to a uniform 

 green. 



An extreme form in the opposite direction is of a rich purple 

 black, the dorsal band darker, edged with white, subdorsal region 

 faintly green tinged, with various oblique lines below. Fig. 3 represents 

 such a larva ; again no two quite alike. A good many larva? made 

 various approaches to this, of which fig. 6 may be taken as an example; 

 and from this to the green form, an intermediate series might be 

 selected, of which fig. 1 would be one form. These intermediates 

 (figs. 1 and 6) were really very handsome, richly coloured caterpillars. 

 The intermediate larva?, however, by no means represented a regular 

 gradation. Some, for example, of the darkish larva? have the white 

 lines pink, and the whole larva then presents a ruddy tint. 



The markings, in a specimen in which they are well seen, generally 

 a darkish one something like fig. 6, present a purplish black 

 dorsal line with whitish border ; a dark band below this has a pale 

 upper margin, uniting at each end of segment with the white line above, 

 forming a pale kidney-shaped mark with greenish -purple centre. 

 Below this dark band, is a double pale greenish line with purplish 

 between, with again purple above the rather bright white lateral line. 

 These purple marks are the usual oblique lines of the slope, and really 

 continue over three segments from before backwards. Below the 

 lateral line is a purple band merging into the greenish underside. The 

 fans are two pale conspicuous spots. 



The pupae are securely fastened by the cremaster and by a slight girth 

 across the first abdominal segment. Length, 9 — 10 mm., a depression dorsally 

 at 3 mm. from front at junction of thorax and abdomen. Height and width at 



