432 HEAD AND NECK 



and which are specially concerned in receiving the impressions 

 of taste. 



Papillae Linguales. These are of four kinds, and differ 

 in size, shape, and in the position they occupy on the 

 surface of the tongue. They are termed the vallate, the 

 fungiform, the conical, and the filiform. 



Papilla Vallata. The vallate papillae (O.T. circumvallate), 

 seven to twelve in number, are the largest, and are placed 

 immediately anterior to the sulcus terminalis, in two rows 

 which diverge from each other in an antero-lateral direction, 

 like the two limbs of the letter V. The foramen caecum 

 lies immediately posterior to the median vallate papilla, which 

 forms the apex of the V. In form, a vallate papilla is 

 broad and somewhat cylindrical, slightly narrower at its 

 attached than at its free extremity, and it is sunk in a pit. 

 It is thus surrounded by a deep trench, the outer wall of 

 which, termed the vallum, is slightly raised beyond the general 

 surface of the mucous membrane, and forms an annular eleva- 

 tion which encircles the free extremity or summit of the 

 papilla. 



Papilla Fungiformes. The fungiform papillae are much 

 smaller, but are present in much greater numbers. They are 

 found chiefly on the tip and sides of the tongue, but they are 

 scattered at irregular intervals over the dorsum also. Each 

 papilla presents a large, full, rounded, knob-like extremity, 

 while it is greatly constricted at the point where it springs 

 from the mucous surface. In the living tongue the fungiform 

 papillae are distinguished by their bright red colour. 



Papilla Conica. The conical papillae are present in very 

 large numbers. They are smaller than the fungiform variety, 

 and although they are quite visible to the naked eye they 

 can be more conveniently studied by the aid of an ordinary 

 pocket lens. They are minute conical projections which 

 taper towards their free extremities, and they occupy the 

 dorsum and sides of the tongue anterior to the sulcus 

 terminalis. They are arranged in parallel rows which are 

 placed close together, and in the posterior part of the dorsum 

 these diverge from the median sulcus in an antero-lateral 

 direction. Towards the tip of the tongue the rows of conical 

 papillae become more or less transverse in direction, and on 

 the sides of the tongue they are arranged perpendicularly. 



Papilla Filiformes. The filiform papillae are similar in 



