THE PALATE. 



97 



at the inner surface of each of the lips. This membrane is covered 

 with numerous glands, some of which are mucous and some salivary. 



The upper lip is longer and thicker than the lower, and has a 

 vertical depression on the middle of its front surface called philtrum, 

 internally the lips are composed of muscular fibres and fat, externally 

 of skin. 



The Gums are formed of the lining membrane of the mouth, 

 much thickened ; they have great hardness and vascularity, but little 

 sensibility. They include the neck of the tooth, and adhere firmly to 

 the periosteum. 



TONGUE. 



The Tongue is an oblong, flattened, muscular body, which varies 

 in size and shape ; it is the 

 organ of taste, and also of im- 

 portance in speech and masti- 

 cation. Its posterior extre- 

 mity or root arises from the 

 hyoid bone, to which it is at- 

 tached by yellow fibrous tis- 

 sue. Its anterior extremity 

 is called its point or tip ; its 

 intervening portion its body. 



The 7nucoiis covering of the 

 tongue is very thick upon its 

 upper surface, and very thin 

 upon its under surface. Upon 

 its upper surface are a num- 

 ber of projections or papillce 

 of various sizes and shapes ; 

 the largest are eight or nine in 

 number, called papillce rriaxi- 

 'mce, and are situated at the 

 posterior portion of the tongue, 

 in two convergent lines ; they 

 are surrounded by fossae, the 

 largest of which is in the 

 middle, and called the fora- 

 men ccBcum. The smallest 

 papillae are fine and pointed, 

 and are found near the middle 

 of the tongue, and are termed 

 filiform. The intermediate papillae are most abundant, some of them 

 are conical, oihevs fungiform. DifFei-ent functions are attributed by 

 some to these different papillae. 



MmscUs of the Tongue.— Hyo- gloss us.*— Origin, from the base 



9 



