ANATOMY AND PHYSIOLOGY lIl7 
Mid intestine (mesenteron) : ventriculus (stomach). 
Hind intestine (proctodeum) : pyloric valve, ileum, colon, 
rectum, anus. 
Stomodzeum.—The mouth, the anterior opening of the 
food canal, 1s to be dis- 
Fic. 146. 
tinguished from the 
pharynx, a dilatation for 
Feception “oi food. In 
the pharynx of mandib- 
ulate insects the food is 
acted upon by the saliva; 
in suctorial forms the 
pharynx acts as a pump- 
ing organ, in the manner 
already described. 
The wsophagus is com- 
monly a simple tube of 
small and uniform cali- 
ber, varying greatly in 
length according to the 
kind of insect. Passing 
between the commissures 
that connect the brain 
with the subcesophageal 
ganglion (Fig. 113), the 
cesophagus leads grad- 
ually or else abruptly 
into the crop or gizzard, 
or when these are absent, Digestive system of a beetle, Carabus. a, 
anal gland; c (of fore gut), crop; c (of 
directly into the stomach. hind gut), colon, merging into rectum; d, 
ae 6 evacuating duct of anal gland; g, gastric 
In addition to its func- ceca; i, ileum; m, mid intestine; mt, Mal- 
pighian tubes; 0, csophagus; p, proventricu- 
tion of conducting food, ; aa 
-: lus; 7, reservoir.—After Kove. 
the cesophagus is some- 
times glandular, as in the grasshopper, in which it is said 
to secrete the ‘“ molasses ’’ which these insects emit. 
