THE DEFENCES OF CATERPILLARS. 1311 



spiecial nest for the purpose, within which they remain at all times when 

 not feeding, and oftentimes even the greater part of their entire lives, feed- 

 ing as they may do upon the nest itself until they have eaten themselves 

 out of house and home. A good instance of this last propensity is found 

 among the species of Vanessa, all of which construct more or less open 

 nests, but devour the contents and the structure itself of the same. 

 Others forming open nests are some of the species of Polygonia, while 

 nioi'c complete web-concealments are made by the caterpillars of Aglais 

 milberti and some of the Melitaeidi. The mere partial curling of a leaf 

 so as to conceal the sides of the creature lying thereon answers the purpose 

 ofJasoniades glaucus, while its neighbor Euphoeades troilus turns the 

 leaf completely over so that the opposite edges touch. But the group, 

 which above all others contains caterpillars living in concealment is the 

 Hesperidae, the higher Hesperidae making an oval enclosure by strong 

 strands of silk connecting the edges of leaves at wide intervals, while the 

 Pamphilidi construct burrow-like nests by sewing together the edges of 

 neighboring blades of grass ; hardly an instance is known, where one of 

 them lives openly. 



Butterfly caterpillars which live exposed have many of them special 

 modes of guarding against danger, some falling to the ground and curling 

 up at the slightest shock or alarm, such as many of the Melitaeidi in their 

 later stages. Others fall with greater deliberation, first attaching a thread 

 to the leaf from which they drop, such as Hypatus bachmanii and Strymon 

 titus. Others assume a Sphinx-like attitude which they may retain for a 

 long time, as is the case with Vanessa huntera in its eai'lier life, and in this 

 they are sometimes aided by the presence of a special knobbed process on 

 the hunched portions, as in the species of Basilarchia. Others when dis- 

 turbed strike with their mandibles the leaf upon which they are resting, 

 as Vanessa atalanta and Cinclidia harrisii are known to do. Or they may 

 move their heads from side to side, catching their mandibles in the rough- 

 nesses of the leaf, and so produce a grating sound, — a very common 

 trick of the higher Hesperidae. A curious allied habit is found in Laertias 

 philenor, which taps alternately with its front legs upon the leaf repeatedly 

 when disturbed, — a habit I have seen in no other caterpillar. Anosia 

 plexippus again, which, when eating, keeps its anterior flexible filaments 

 constantly in motion forward and backward, moves them with still greater 

 violence when it is in a state of alarm, and this must serve as a very con- 

 siderable protection to it. 



Nearly all caterpillars, whether of butterflies or moths, will, when dis- 

 turbed, throw their heads violently around from side to side in a threatening, 

 angry manner, the head with its hard incasement and biting jaws being 

 the most offensive weapon in the control of the caterpillar. But it is a very 

 curious sight to see how, as impelled by one impulse, the young cater- 



