THE HEAD. 383 



in front with the nostril, and through the naso- 

 palatine canal with the mouth. 



Make a drawing of the dissection to show the farts exposed 

 in this vertical section of the head. 



6. The salivary glands are large and paired. 

 Dissect from the right side. 



a. The parotid gland, the largest of the salivary glands, is a soft 



pinkish mass lying in front and below the external audi- 

 tory meatus, between this and the hinder edge of the 

 mandible. It is very variable in size, and may extend 

 beyond the angle of the jaw and some distance forwards 

 along its inner surface. 



The duct of the parotid, or Stenonion duct, leaves the 

 gland at its anterior border, and runs forwards just 

 beneath the skin, parallel to and about a quarter of an 

 inch below the zygomatic arch. It opens into the mouth 

 by a small aperture on the inner side of the cheek, opposite 

 the second upper premolar tooth. 



b. The infra-orbital gland is an irregular lobulated mass, about 



three-quarters of an inch long, lying below and in front 

 of the eye, partly above the zygomatic arch and partly 

 hidden by it. 



The duct runs doAvnwards to open into the *nouth, 

 close to the Stenonian duct. 



c. The sub-maxillary gland is a compact reddish ovoidal mass, 



lying close to its fellow between the angles of the man- 

 dible, and in front of the larynx (fig. 65, TM). 



The duct, Wharton's duct, leaves the outer side of the 

 gland near its hinder end, and runs forwards along the 

 inner side of the jaw to open into the floor of the mouth 

 midway between the lower incisors and the root of the 

 tongue, the openings of the ducts of the two sides being 

 about an eighth of an inch apart. 



Dissect from the ventral surface. To follow the duct into 

 the mouth, turn the halves of the lower jaw aside. 



d. The sublingual gland is an elongated flattened reddish body, 

 about three-quarters of an inch long, lying along the 

 inner side of the ramus of the mandible, between this and 

 Wharton's duct. 



The ducts open separately on the floor of the mouth. 



