650 MAMMALIA. 



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. Open- 

 ing 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 



Fig. 284.— Diagram of caecum gullet, and that leads through 



in rabbit. the diaphragm to the expanded 



s.i., Small intestine; *.,-■. jaccuius stomach, which is dilated at its 



rotundus; co/., sacculated colon; ... 



c caecum; v.a,, vermiform upper or cardiac end, and nar- 

 appendix. rowg tQ fa e 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 continuous with the colon or first part of the large 

 intestine, the beginning of which is much sacculated. The 

 large intestine narrows into the long rectum, in which lie little 

 faecal pellets. On the last two inches of the rectum there 

 are paired yellowish glands. Beside the anus are two bare 

 patches of skin, with the openings of the ducts of the perineal 



