62 THE ORGANS OF SPECIAL SENSE. 



The parotid gland is the largest and is below and in front 

 of the ear, opening by Stensen's duct. The submaxillary 

 gland is below the jaw toward the back on either side 

 and its duct is Wharton's duct. The sublingual gland lies 

 beneath the mucous membrane of the floor of the mouth 

 and opens by eight to twenty tiny ducts beside the fre- 

 num, the ducts of Rivinus. The activity of the glands 

 depends upon the blood supply; the more blood the 

 greater their activity. 



FIG. 20. Dissection of the side of the face, showing the salivary glands: a, 

 Sublingual gland; b, submaxillary gland, with its duct opening on the floor of the 

 mouth beneath the tongue at d; c, parotid gland and its duct, which opens on the 

 inner side of the cheek. (After Yeo.) 



The Tonsils. The tonsils vary in size and in tonsillitis 

 swell and may even meet in the median line. They are 

 frequently removed. When they are enlarged one often 

 gets a third tonsil or adenoids, a lymphoid growth at the 

 back of the pharynx which causes mouth-breathing by 

 day and snoring by night. A child with adenoids is 

 starved for air and what air is breathed in is not warmed. 

 The growth should be removed. 



A short frenum produces tongue-tie, which may be 

 remedied by snipping. Cancer of the tongue is fairly 

 common and necessitates a radical operation. In 

 mumps the parotid glands are inflamed and enlarged. 



