

THE TONGUE. 15 



rows, which in general run parallel to the latter, and pass, upon 

 the border of the tongue, into laminated, sometimes not even 

 notched folds, which can no longer be considered as papilla. 

 The papilla fungiformes or clavata are 0*8"' — 0-8'" in length, 

 0*2 — 05'" in breadth ; they have smooth surfaces and, during 

 life, are readily recognised by their red colour; they abound 

 particularly upon the anterior half of the tongue, scattered over 

 its surface at tolerably regular intervals of \ — 1'" and more; and 

 at the point, indeed, they are often so thickly crowded as to be 

 in contact ; they are not absent, however, upon the posterior half, 

 as far back as the papilla circumvallata. The papillae filiformes or 

 conicce of i — 1±"' length, and O'l'" — 0'2 /// breadth, are rendered 

 very obvious by their number and whitish colour ; they occupy, 

 in close contact with one another, the intervals between the 

 fungiform kind, and invariably appear most densely crowded 

 and best developed, with brush-like ends, in the concave side 

 of the V of the circumvallate papilla, and in the middle line of 

 the centre of the tongue. Towards the edges and the point, 

 the papilla themselves, as well as their processes, become shorter, 

 and to some extent more scanty, so that they gradually pass 

 into the lamina to which we have referred, and also in many 

 respects approximate the fungiform papilla; from which, in fact, 

 so far as the structure of their surface is concerned, they be- 

 come hardly distinguishable. 



Besides these papilla which project freely, there may also be 

 observed over the whole gustatory region of the tongue, smaller 

 ones completely buried in the epithelium, which are perfectly 

 similar to those of the non-gustatory parts of the organ. 



With respect to the minuter structure of the mucous mem- 

 brane of the tongue, that part of it which presents no projecting 

 papilla, differs in no respect from the mucous membrane of 

 the oral cavity, and possesses, in fact, a laminated pavement 

 epithelium of 0*045"' thickness at the root of the tongue, of 

 006 — 01'" on the lower surface of its apex, with simple small 

 imbedded papilla of 0-024— 0-05"' length, 0*004— 0-02'" 

 breadth, which are not absent even upon the anterior surface 

 of the epiglottis, and between it and the papilla circumval- 

 lata. In the proper gustatory region of the tongue the sub- 

 mucous tissue is wholly absent, the mucous membrane being 

 united with the muscular substance by means of a dense layer 



