THE SALIVARY GLANDS. 



363 



and form the salivary alveoli. These are lined by salivary 

 cells, uninucleated granular cells, which almost entirely 

 fill the alveoli. Interposed between the cells and base- 

 ment membrane are collections of minute, dark, granular 

 cells, forming zones and crescents. The external carotid 

 artery is deeply imbedded in the substance of the parotid 

 gland, and the posterior auricular and transverse facial 

 are given off in its substance. The facial nerve enters 

 its inner posterior part and emerges near its anterior 

 border. The duct of the parotid, or Steno's duct, is about 

 two and a half inches long ; it runs transversely across 



FIG. 158. .SECTION OF A SALIVARY GLAND. 



the masseter on a level with the necks of the upper teeth, 

 then pierces the buccinator and opens on a papilla just 

 above the upper second molar. It is about one-eighth 

 of an inch in diameter, and feels like a whip-cord. It 

 presents three coats, outer or fibrous, muscular, and mu- 

 cous. 



The siibmaxillary gland is situated beneath the mylo- 

 hyoid muscle, in the submaxillary triangle, under cover 

 of the inferior maxillary bone. It weighs about two 

 drachms, is about one and a half inches long, and has 

 a single duct, the duct of AVharton, which opens at 



