STATES OF INSECTS. 225 



intended for this very purpose : and, according to Reau- 

 mur, a similar powder, but white, derived from the vari- 

 cose intestines, is used by the caterpillars of Gastropacha 

 quercifolia, &c. a The other material, which is still more 

 frequently employed, and which is occasionally mixed 

 with the former, is the hair which every one has observed 

 to cover so thickly the bodies of some caterpillars. This, 

 after spinning a sufficient envelope, they tear, or in some 

 instances cut off with their mandibles, and distribute all 

 round them, pushing it with their head amongst the in- 

 terstices of the silk, so as to make the whole of a regular 

 thick texture. After this process, which leaves the body 

 completely denuded, and often seems to give them great 

 pain, they conclude by spinning another tissue of slight 

 silk, in order to protect the forthcoming pupa from the 

 surrounding prickly points. It should be observed, how- 

 ever, that though many hairy larvae, as those of Noctua 

 Aceris, Arctia Caja, and others, employ their hairs in the 

 composition of their cocoons, the rule is not general, 

 several never making any such use of them. Nor do all 

 that do so employ them distribute them in the same man- 

 ner as those above described, which rarely attempt to 

 arrange them in any regular position. Reaumur has no- 

 ticed a small hairy caterpillar that feeds on lichens, which 

 is more methodical : this actually places its hairs upright, 

 side by side, as regularly as the pales in a palisade, in 

 an oval ring around its body, connecting them by a slight 

 tissue of silk, which forces them to bend into a sort of 

 roof at the top ; and under this curiously-formed cocoon 

 assumes its state of pupa b . Some larvae make so much 



a Reaum. ii. 284. b Ibid. i. 524. 



VOL. III. O 



