HO 



ZOOLOGY. 



/NTfifi/AL. 

 /VA#J 



The throat gradually narrows back into the oesophagus 

 and stomach, no sharp limit being discernible between them : 

 the stomach is simply a part of the general tube in which 



the peptic glands 

 are developed. 

 It is, however, 

 separated from 

 the duodenum 

 by a sphincter 

 muscle. The 

 duodenum (recog- 

 nizable as such 

 by receiving the 

 secretions of liver 

 and pancreas) is 

 short, and is 



' , , 



bent back par- 

 allel to the 

 stomach. In the 

 mesentery be- 

 tween them lies 

 the pancreas, 

 which is a com- 

 pact gland, not 

 diffuse^ as in tKe 

 rabbitT The liver 

 is large, and con- 

 sists of a right 

 and left lobe, the 

 latter partially 

 subdivided ; the 

 gall - bladder is 

 spherical. The 

 pancreas sur- 

 rounds the course 



of the bile-duct, and has no separate duct of its own, its 



ductlets opening into the bile-duct. 



The duodenum passes on into a portion of the canal that 



is thrown into a series of simple folds : this is the ileum. 



There are no Peyer's patches, and it does not end in a 



Fig 68. ALIMENTARY CANAL OF FROO. 



The left side of mouth and throat has been cut through, 

 and the floor turned over to the animal's right (left of 

 diagram). The dotted line around the glottis is the 

 outline of the laryngo-tracheal chamber. 



