134 
ANATOMY AND PHYSIOLOGY 
adhering to the more simple division and nomencla- 
ture indicated on a former page. It will be seen, 
moreover, that two of the parts which we have not 
regarded as entitled to a separate consideration, the 
duodenum and the colon, are thought to exist in only 
a veiy few species, and even then they are not par- 
ticularised by any one constant character. 
The intestine commences immediately behind the 
chylific ventricle, from which it is separated by an 
annular constriction or sphincter. This alone points 
out its origin, when the biliary vessels are placed 
towards the anus ; but being usually inserted imme- 
diately beneath the sphincter in question, they then 
mark precisely its anterior limit.* The small intes- 
tine, in its ordinary state, is a slender simple tube, 
very variable in length. In general, it is a good deal 
shorter than the body, frequently shorter than the 
chylific ventricle, (as in the Chrysomelidce.) some- 
times it attains the length of the body, and in a few 
instances exceeds it. In certain cases it deviates 
from a simple tubular form, and becomes inflated 
more or less abruptly into a clavate or oval-shaped 
bag. This is well exemplified in the common cock- 
chafer, (Plate II. fig. 3 f y ) where it forms a large 
ovoid pouch, and presents, when distended, five pro- 
jecting ribs, which correspond to a scries of im- 
bricated plates in the interior. In this case there is 
an additional inflation, of much smaller size, a little 
behind the principal one. " If the name of this por- 
Lacord. Intro. II. 33. 
