THE RABBIT 



441 



the total for both sides being 28. Four pairs of salivary 

 glands pour their secretion into the mouth. The parotid 

 gland of each side lies behind the angle of the jaw, 

 the submaxillary gland lies against its fellow between the 

 angles of the jaw, the infraorbital gland lies below the eye 

 behind the cheek-bone, the sublingual gland lies along the 

 inside of the mandible. The saliva moistens the food and 

 contains an enzyme, known as ptyalin, which turns starch 

 into sugar. The pharynx re- 

 ceives in front the narial 

 passage and the mouth. Be- 

 hind, it leads into the gullet 

 above and bears below the 

 glottis, which lies shortly be- 

 hind the tongue, covered by 

 a flap, known as the epiglottis, 

 which is stiffened by a car- 

 tilage. Thus in the pharynx 

 there cross one another the 

 passages by which the food 

 passes to the alimentary canal 

 and the air to the lungs. In 

 swallowing, the soft palate is 

 raised and thus closes the 

 posterior nares, while the epi- 

 glottis protects the opening of 

 the windpipe, so that when Fig. 323.— The duodenum of a 

 the food is thrust backwards ^^Be^aT' ™ ^ 

 bv the muscles of the tongue 



* j i_ •. „ „„„ „„ i . P., Pyloric en4 of stomach: g.b.. gall 



and pharynx it passes only bl l dder with bile duct a ' n J h( y| tic ■ 



into the CeSOphagUS. That ducts ;>.rf., pancreatic duct. 



tube runs backwards through 



the neck and chest, above the trachea. 



Shortly after passing through the diaphragm, the 



oesophagus joins the stomach. This is a wide 

 fntestine. 31 " 1 sac > placed athwart the body cavity and wider 



at the left or cardiac end than at the right or 

 pyloric end; it is curved, with the concave side turned - 

 forwards, and the oesophagus enters at the bottom of 

 the concavity. The pyloric end communicates with the 

 intestine by a small opening, the pylorus, provided with a 

 29 



