78 
COMPARATIVE ZOOLOGY. 
Lobster, have a ’short gullet leading to a large cavity, sit¬ 
uated in the front of the animal, which is a gizzard, rather 
than stomach, as it 
has thick muscular 
walls armed with 
teeth. A well- 
marked constric¬ 
tion separates this 
organ from the in¬ 
testine. The “liv¬ 
er, 5 ’ really a pan¬ 
creas, is highly 
developed; instead 
of numerous folli¬ 
cles, there is a 
large bilaterally 
symmetrical or¬ 
gan, divided into 
three lobes on each 
side, pouring its 
secretion into the 
upper part of the 
intestine, which is 
the true stomach. 
Among Insects, 
there is great vari¬ 
ation in the form 
and length of the 
canal. The follow¬ 
ing parts can gen¬ 
erally be distin¬ 
guished : gullet, 
crop, gizzard, stomach,and large and small intestines, with 
many glandular appendages. The crop, gizzard, and large 
intestine are sometimes absent, especially in the carnivorous 
Fm. 40.—Anatomy of a Caterpillar: cj, h , oesophagus; h, 
i, stomach ; k, hepatic vessels; l , m, intestine ; q, r, sal¬ 
ivary glands; p, salivary duct; a , b, c, longitudinal 
tracheal trunks; cl, e, air-tubes distributed to the vis¬ 
cera; /, fat-mass; v, x, y, silk-secretors ; z, their ex¬ 
cretory ducts, terminating in t , the spinneret, or fu- 
siilus. 
