I.] DISSECTION OF A RABBIT AND OF A DOG. 25 



forwards across the masseter muscle to their 

 endings in certain muscles of the face. 



3. The duct of the parotid (duct of Stenson) 

 runs forward with the facial nerve, from the 

 gland; it is small, thin-walled and inconspicuous, 

 it may sometimes be made evident by. pressing 

 on the gland and so forcing some fluid into it. 

 The branches of the facial should be carefully 

 isolated close to the gland, the connective tissue 

 being cut through with a fine pair of scissors as 

 close as possible to the nerves lest the duct be 

 inadvertently severed ; on pulling the nerves to 

 one side the duct will be seen, follow it forwards 

 to the anterior edge of the masseter where it 

 dips down to the mouth ; make a small cut in it 

 with scissors and pass a bristle down it. 



In the dog the duct is much more obvious, the 

 facial nerve does not accompany it. 



4. Cutting through the parotid gland, trace the 

 facial nerve to its exit from the skull by the 

 stylo-mastoid foramen ; observing the branches 

 going to the muscles of the ear. 



5. Behind the parotid gland will be seen a nerve 

 running from the under surface of ,the stemo- 

 mastoid muscle (cp. C. § 21) dividing into two 

 branches, and passing up the ear. This is the 

 great auricular, which arises from the 3rd 

 cervical nerve, and is the main sensory nerve 

 for the ear. Trace as far as possible its course 

 in the ear. 



