OF LEPIDOl'TEllOUS !^SECTS- 75 



which they pass. In most of these last the rings are quite hard, and 

 tlicir body resembles a little branch of a tree or a small piece of wood, 

 whence they have received the name of Rod-measurers^ ( Arpenteiises en 

 halon.) Whilst in repose they hold themselves upright, clinging by 

 their hind legs to the petiole of a leaf or a young bianch in attitudes so 

 fatiguing that it must require great muscular power to retain that posi- 

 tion for hours, as they do.* 



Caterpillars are more or less vivacious, according to the genus : there 

 are some very sluggish, as those of the Papillonidac, Lycaenidae, etc. ; 

 but none is so slow as the Limacodcs in which the membranous feet are 

 replaced by rows of buttons that are capable of retraction and emit a 

 viscous matter analagous to that secreted by the snail. A great many 

 Geometrae allow themselves to be handled like a piece of wood without 

 showing any signs of life. On the contrary, most of the Cheloniae are 

 very lively and run with great speed. 



The locomotion of caterpillars is almost always performed from rear 

 to the front ; yet the Herminiae, many of tlic' Bolys^ Tincidac and Tor- 

 trices move backwards with great rapidity, and, when they are disturbed 

 or an attempt made to seize them, they make short leaps in older to 

 escape, as Degecr has observed in the Hcrminia roslralis ; but these 

 leaps are not to be compared to those of the Calocalac wliich arc aston- 

 ishing, being perfect somersets. 



Besides appendages of diflerent kinds, such as hair, spines, See. which 

 are found upon the bodies of most caterpillars, in some species we find 

 two retractile tentacula, or feelers, placed upon the anterior edge of the 

 first ring, which the animal puts out and in at pleasure, like the tentacula 

 of snails. This is the fact with the genus 'J'hais^ notwithstanding La- 

 treille's assertion to the contrary. They range in length and color ac- 

 cording to the species, but generally they unite at the base so as to ap- 

 pear in the shape of a Y. 



As to clothing caterpillars are smooth, pubescent, hairy, brisllv, 

 rough, spiny, callou.-'. Sec. Some though destitute of bristles have upon 

 their backs protuberances which give them a very queer appearance, 

 such are the JVotndonla torva, Dromednrius^ etc., or callous tubercles 

 resembling the buds of a tree or a sort of knots, as in many Geometrae. 

 The caterpillars of nearly all the Sphingidae and of some Bombycidae, 

 have, upon the eleventh ring, a kind of conical horn, fleshy at its base, 

 and horny at its extremity, sometimes smooth and sometimes rough. 

 This organ is generally curved towards the hinder part of the insect. — 



*Lyonet counted 1011 muscles in tlic caterpillar of the Cossus Lis:niperda. 



CUVIKK. 



