3^4 



CHOKDA'J'A. 



another cavity (the thoracic cavity) containing, as will be 

 seen, the heart and lungs. 



The buccal cavity can be exposed by cutting one man- 

 dible. The tong2ie is large and mobile, and behind its base 

 Alimentary ^^ glottis covered by a flap, the epiglottis. 



The internal nares open very far back, almost 

 over the glottis. This is due to the formation of a 

 palate or secondary roof to the buccal cavity which shuts 

 off a complete nasal chamber, at the hind-end of which 

 open the two Eustachian apertures. 



Fig. 277. — Permanent Dentition of the Hare 

 {Leptts tijiiidus). 



Note the long incisors, four above and two below, and the cheek-teeth -^' 



2.3. 



Into the mouth there open the ducts of four pairs of 

 salivary glands — the parotid^ below the ear ; the infra-orbital^ 

 below the eye; the submaxillary^ between the mandibles; 

 and the sublingual gland, under the tongue. These secrete 

 saliva which is mixed with the food by mastication and has 

 a digestive action on certain foods. 



At the anterior end of the jaws is a pair (upper and 

 lower) of large sharp-edged incisor teeth. These have hard 

 enamel mainly on the outer surface and are kept sharp by 

 wearing upon each other. They grow throughout life as 



