118 POLYOMMATUS (LYOJ]NA) AGESTIS. 



depression ; its colour, a pale greenish- drab, continues 

 to the last. A hole in the shell betrays the escape of 

 the larva, which is a very sluggish little creature, not 

 inclined to leave the underside of the leaf where it is 

 hatched, even when the leaf has become dry ; indeed, 

 all the leaves on which the eggs were laid had curled 

 and shrivelled so much when the larva were hatched, 

 as to make their detection and rescue while alive 

 rather difficult. 



I observed the first three larvse on the 19th of 

 September, one of them already dead, and on the 22nd, 

 eighteen more, with some of them apparently dead or 

 dying. 



A month previously I was provided with a very large 

 pot of turf cut from a chalk hill, and amongst grasses, 

 Leguminosce, and other low plants, some fine shoots of 

 Helianthemum vulgare were also growing ; on these 

 last the young larva3 were placed. Next morning, 

 about half of them lay dead, and the others had dis- 

 appeared. But after a day or two I began to detect 

 signs of the survivors, by small flesh-coloured spots 

 appearing on the upper dark green surface of a few of 

 the leaves ; these spots gradually increased in size to 

 blotches of irregular figure, and turned of a rusty pale 

 brown colour; when seen from beneath against the 

 light, they appeared semitransparent and colourless, 

 and sometimes then the tiny larvas appeared as a dark 

 object against the luminous blotch. 



By the 20th of October a few leaves had their lower 

 cuticle almost entirely eaten away, and their upper 

 surface turned brown, but so slow was the growth of 

 the larvse that they had only attained one line in 

 length by the 3rd of November, and though they fed a 

 little at intervals, and crept from one part of their 

 food to another up to the end of the month, yet they 

 were never seen on any of the other plants around 

 them, but only on the under surface of the leaves of 

 Helianthemum, where they became eventually fixed for 

 hibernation. 



