190 Insect Architecture. 



rather difficult to bend ; but the caterpillar is four times as 

 large and strong as those which we have been hitherto de- 

 scribing. In some seasons it is plentiful ; in others it is 

 rarely to be met with : but the admiral is seldom scarce in 

 any part of the country ; and by examining the leaves of 

 nettles which appear folded edge to edge, in July and 

 August, the caterpillar may be readily found. 



Another butterfly (Hesperia malvce) is met with on dry 

 banks where mallows grow, in May, or even earlier, and 

 also in August, but is not indigenous. The caterpillar, 

 which is grey, with a black head, and four sulphur-coloured 

 spots on the neck, folds around it the leaves of the mallow, 

 upon which it feeds. There is nothing, however, pecu- 

 liarly different in its proceedings from those above de- 

 scribed ; but the care with which it selects and rolls up 

 one of the smaller leaves, when it is about to be transformed 

 into a chrysalis, is worthy of remark ; it joins it, indeed, so 

 completely round and round, that it has somewhat the 

 resemblance of an egg. Within this green cell it lies secure, 

 till the time arrives when it is ready to burst its cerements, 

 and trust to the quickness of its wings for protection against 

 its enemies. 



Among the nests of caterpillars which roll up parcels of 

 leaves, we know none so well contrived as those which are 

 found upon willows and a species of osier. The long and 

 narrow leaves of these plants are naturally adapted to be 

 adjusted parallel to each other; for this is the direction 

 which they have at the end of each stalk, when they are 

 not entirely developed. One kind of small smooth cater- 

 pillar (Tortrix chlorana), with sixteen feet, the under part 

 of which is brown, and streaked with white, fastens these 

 leaves together, and makes them up into parcels. There is 

 nothing particularly striking in the mechanical manner in 

 which it constructs them. It does precisely what we should 

 do in a similar case : it winds a thread round those leaves 

 which must be kept together, from a little above their ter- 

 mination to a very short distance from their extreme point ; 

 and as it finds the leaves almost constantly lying near each 



