78 



COMPARATIVE ZOOLOGY. 



Lobster, have a short gullet leading to a lurge 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," really a pan- 

 creas, is highly 

 developed; instead 

 of numerous folli- 

 cles, there is a 

 large bilaterally 

 symmetrical or- 

 gan, divided into 

 th ree 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 



Fia.iO.-AnatomyofaCaterpillav: y, Mesophagns; h, length of the 



!', stomach,- *, hepatic vessels ; !, m, intestine ; j,r, sal- Canal. The foUoW- 



ivaiy glands; p, salivary duct; a, b, c, longitudinal • 



tracheal trunks ; d, e, air-tubes distributed to the vis- ^''S partS Can gCH- 



cera; /, fat-mass j », a;, y, silk-secretors; z, their ex- p-all-ir K^ AU^i^ 



cretory ducts, terminating in (, the spinneret, or /«- '"'^"J "6 QlSim- 



""™- 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 



