ALIMENTARY SYS TEAL 



685 



Alimentary system. In connection with the cavity of 

 the mouth we notice the characteristic dentition, the hairy 

 pad of skin intruded in the gap between incisors and pre- 

 molars, the long and narrow, in part bony, palate separating 

 the nasal from the buccal cavity, the muscular tongue with 

 its taste papillae, the glottis which leads into the windpipe, 

 and the bilobed flap or epiglottis which guards the opening, 

 the paired apertures of the Eustachian tubes opening into 

 the posterior nasal passage, the end of this passage above the 

 glottis, and the beginning of the pharynx. Less obvious 

 are the organs of Jacobson, paired tubular bodies lying en- 

 closed in cartilage in the front of the nasal chamber, and 

 communicating on the one hand with the nostrils, and on the 

 other hand with the mouth by 

 two naso-palatine canals which 

 open a little way behind the 

 posterior incisors. Opening into 

 the mouth and conducting the 

 salivary juice, whose ferment 

 alters the starchy parts of the 

 food, are the ducts of four pairs 

 of salivary glands. The parotid, 

 which is largest, lies between 

 the external ear-chamber and the 

 angle of the mandible ; the 

 infra-orbital lies below and in 

 front of the eye ; the sub- 

 maxillary lies between the angles 

 of the mandible ; the small sub- 

 linguals lie along the inner side of each ramus of the mandible. 



The pharynx passes into the gullet, and that leads through 

 the diaphragm to the expanded stomach, which is dilated 

 at its upper or cardiac end, and narrows to the curved 

 pyloric end. Partly covering the stomach is the large liver. 

 The first portion of the intestine, which is called the 

 duodenum, receives the bile duct, and has the pancreas in 

 its folds. Then follows the much-coiled small intestine, 

 measuring many feet in length. The lower end of the small 

 intestine is expanded into a sacculus rotundus. Here the 

 large caecum a blind diverticulum is given off; it ends in 

 a finger-like vermiform appendix. Its proximal end is con- 



cdl 



FIG. 338. Diagram of crecum 

 in rabbit. 



s.i., Small intestine; s.r., sacculus 

 rotundus ; col., sacculated colon ; 

 c. , caecum; P. a., vermiform 

 appendix. 



