PAPILLAE OF THE TONGUE. 465 



when the tongue is raised it is particularly conspicuous : it is 

 called the Sublingual. 



The lining membrane of the mouth continues from the inside 

 of the alveoli of the lower jaw, which it covers, over the sublin- 

 gual glands to the lower surface of the tongue. In this situa- 

 tion it is remarkably thin ; but, as it proceeds to the upper 

 surface of the tongue, its texture changes considerably, and on 

 this surface it constitutes the organ of taste. 



The upper surface of the tongue, although it is continued 

 from the thin membrane above described, is formed by a 

 rough integument which consists, like the skin, of three lamina. 

 The cuticle is very thin ; and under it, the rete mucosum* is 

 thicker and softer than in other places. 



The true skin here abounds with eminences of various sizes 

 and forms, all of which are denominated Papilla. The largest 

 of these are situated on the posterior part of the tongue, and 

 are so arranged that they form an angle rather acute, with its 

 point backwards. They are commonly nine in number : they 

 resemble an inverted cone, or are larger at their head than their 

 basis. They are situated in pits or depressions, to the bottoms 

 of which they are connected. In many of them there are 

 follicles, or perforations, which have occasioned them to be 

 regarded as glands. They are called Papilla Maxima, or 

 Capitata. 



The papillae, next in size, are denominated fungiform by 

 some anatomists, and Media or Semilenticulares by others. 

 They are nearly cylindrical in form, with their upper extremi- 

 ties regularly rounded. They are scattered over the upper 

 surface of the tongue, in almost every part of it, at irregular 

 distances from each other. 



The third class are called conoidal or villous. They are 

 very numerous, and occupy the greatest part of the surface of 

 the tongue. Although they are called conoidal, there is a great 



* M. Bichat appears to have had doubts whether the real rete mucosum 

 existed here. He says that he could only perceive a decussation of vessels in 

 the intervals of the papillae, which, as he supposes, occasioned the florid color 

 of the tongue. 



