OTHER ORGANS OF DIGESTION. 59 



c. The large circular muscle is the diaphragm and sepa- 

 rates the thoracic and the abdominal cavities. 



d. Sketch. 



B. The Alimentary Canal. 



I. THE TEETH. 



Examine the teeth and compare them with the human 

 teeth. 



a. How many incisor teeth are there ? 



1. What is peculiar about them ? 



2. What is the purpose of this ? 



b. How many canine teeth has the rabbit ? 



c. Find the premolar teeth. 



d. Are there any molar teeth ? 



e. What is the dental formula of the rabbit ? 



II. THE MOUTH, OK BUCCAL CAVITY. 



Notice its general shape and size. 



III. THE PHARYNX, OR THROAT CAVITY. 



a. Can you find the nasal openings on the dorsal surface ? 



1. How many are there? 



b. Look carefully on the sides for the openings into 

 the Eustachian tubes. Pass a bristle along one tube into 

 the middle ear. 



c. On the ventral surface of the pharynx look for the 

 opening into the windpipe, the glottis. Which way 

 does the lid, or epiglottis, open ? 



