1 88 THE BOOK OF BRITISH BUTTERFLIES. 



L. astrarche, Bergstrasser, medon, Esper, agestis, 

 Hiibner, idas, Haw. (Brown Argus) (Figs. 209 to 211), 

 although belonging to the family of Blues, has not a 

 particle of blue about it. This inconspicuous little 

 butterfly is well distributed, and usually plentiful in 

 England and the southern half of Scotland ; but so 

 greatly does it vary with change of latitude that many 

 have been the discussions and controversies amongst 

 naturalists as to whether the different forms should 

 constitute one, two, or even three species. The weight 

 of the evidence seems, however, to be in favour of 

 considering them all to belong to one, though the 

 southern and typical form is double-brooded, while the 

 others pass through the cycle of changes but once in a 

 season. 



The eggs of the typical form are laid twice in the 

 year, about May and August, in small groups on the 

 under-surface of the leaves of the Common Rock-rose 

 (Hclianthemum vulgare), and also on the Hemlock Stork's- 

 bill (Er odium dcutariunt). The larvae of the second 

 brood pass the winter in that stage, and assume the 

 pupal form about the end of April. The imagines of 

 the typical form appear in May and again in August ; 

 but those of the northern forms do not appear till the 

 end of June. 



The larva (Fig. 209) is about Jin. in length and of 

 the form common to the genus. The colour is pale 

 green with a medio-dorsal brownish-purple stripe, and on 

 each side very faint pale oblique stripes, which, in the 

 northern form at least, disappear when the larva is 

 nearly full-grown. There is also a lateral pink stripe 

 on each side, edged with darker pink above and still 

 darker below. The pale, inconspicuous spiracles are 

 situated in the uppermost pink stripe. The dorsal 



