78 



COMPARATIVE ZOOLOGY. 



Lobster, have a short gullet leading to <t 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," 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 yari- 

 ation in the form 

 and length of the 



Pi. 40. Anatomy of a Caterpillar : w, h, oesophagus ; ft, , . . .... 



?', stomach ; k, hepatic vessels ; I, m, intestine ; q, r, sal- Canal. 1 lie lOllOW- 



ivary glands; p, salivary duct; a, b, c, longitudinal ,' no , TIQr i. a ,, QT1 



tracheal trunks; d, e, air-tubes distributed to the vis- 11J & P^ 1 tb LdIJ 



cera; /, fat-mass; v, x, y, silk-secretors ; z, their ex- prallv KP 

 cretory ducts, terminating in t, the spinneret, or fu- " * 



'^- 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 



