112 STATES OF INSECTS. (Larva.) 
semble a piece of crystal, and scarcely to be distinguished 
from the water in which it lives *. 
ii. Parts. The body of each larva consists of the head, 
including its different organs, and of the succeeding seg- 
ments, of which the three first may usually be denomi- 
nated the trunk, and have the six anterior feet, when 
present, attached to their under side: the remainder is 
the abdomen. ‘The latter includes in some species a vari- 
able number of membranous feet, as well as various ap- 
pendages affixed usually to its tail and sides. No larva 
is ever furnished with wings®. Each of these greater 
divisions, and the organs which they include, require 
separate consideration. 
1. Head. This, as was lately observed, is exteriorly of 
a horny substance, or at least harder than the rest of the 
body, in most larvee; and on this account, though rarely 
separated from it by any visible distinct neck*, is, if the 
* Reaum. v. 40. ¢. vi. f. 4—15. 
> Miiller, the Danish zoologist, relates, that he once met with a 
papilio which, with the true wings of the genus, had a head without 
antenne or tongue, furnished with mandibles ; and, in short, that ofa 
true caterpillar. It wasa female, which deposited eggs that proved 
barren. If this solitary instance was not a mistake, is it possible that 
some parasitic larva had devoured only the inclosed head of the but- 
terfly, or so injured it that it could not reject the hard skin of the 
larva, and yet not be destroyed ? 
¢ The only larvze which have a visible distinct neck are those of 
some Dytisci, Staphylini, and a few others, in which this part is quite 
distinct : proving the erroneousness of the opinion of those German 
entomologists, who consider the thorax as analogous to the neck of 
other animals, and hence call it Halsschild. In some lepidopterous 
larvee, however, as in that of Pontia Brassica, though no visible neck 
presents itself, one is very perceptible when the insect stretches the 
head forward considerably. Reaum. i. 460. 
