78 



COMPARATIVE ZOOLOGY. 



the Lobster, have a short gullet leading to a large cav- 

 ity, situated in the front of the animal, which is a giz- 

 zard, 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 liver 

 is highly devel- 

 oped ; 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 



mm &, 



m j| pf Jj- 



Fis. 40. Anatomy of a Caterpillar: y, h, oesophagus; h, 



canal. Thefollow- 



j, stomach ; k, hepatic vessels ; I, m, intestine ; q, r, sal- 



ivni-y glands ; p, salivary duct ; a, 6, c, longitndinnl 



trachenl trnnk* ; rf, e, air-tubes distributed to the vis- * n g P arts Can 



cera; /, fat-mass; v, x, y, silk-secretors ; z, their ex- Ora 11 v ] )P 



cretory ducts, terminating in t, the spinneret, or fu- G1 l 



f- 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 



