132 
ANATOMY AND PHYSIOLOGY 
that derive their nourishment from decomposed vege- 
table or animal matter. For the most part, only 
two of the membranes which enter into the general 
composition of the tunic of the intestinal canal can 
he detected here, the innermost of which is almost 
corneous and much folded. These folds are not 
accidental, but are arranged in a certain order, 
according to the genera and families. The gizzard 
is wanting in the larvae of all insects which go 
through a complete metamorphosis. The ckylific 
ventricle, (Plate II. fig. 2 and 3, d.) is the ensuing 
dilatation of the intestinal canal ; an important cavity 
which, upon the whole, may be regarded as most 
nearly corresponding to the stomach of the verte- 
brata. The above name, assigned to it by M. Leon 
Dufour, is exactly expressive of its function, which 
is to contain the food, now reduced to a homo- 
geneous and impalpable pulp, till it undergo the pro- 
cess of cliylification. Its capacity is considerable, 
either arising from its width or length. Its termina- 
tion behind is indicated by the insertion of the biliary 
vessels, or by a constriction separating it from the 
small intestine. In form, it is always more or less 
tubular, or tending to oval, hut even within these 
limits the shape varies much. In the common cock- 
chafer, (PI. II. fig. 3 d 3 ) it is contracted behind into a 
long tube, and twisted into several circumvolutions — 
a mode of disposition which it frequently exhibits in a 
still more complicated maimer in some of the other 
orders. One of the most distinctive and remarkable 
characters of this ventricle, is the palpillte or small 
