THE TONGUE, BY E. KLEIN. 515 



membrane which surrounds them ; and this is so indistinct in 

 most instances in newly born children, that no difference can 

 be discerned between them and the clavate papillae. As regards 

 the distribution of these various papillae on the tongue of Man, 

 the papillae filiformes are spread in nearly equal numbers over 

 the whole dorsal surface of the horizontal part, and on the edges. 



The fungiform papillae are found on the anterior portion of 

 the dorsal surface, and chiefly near the tip and edges ; towards 

 the median line of the posterior portion they become more 

 sparing and small, and altogether cease at the root of the 

 tongue. It only happens in some few cases that filiform 

 papillae are found in the latter region, and still more rarely the 

 fungiform. 



The papillae circumvallatae are most limited in number; they 

 are placed on each half of the tongue at the junction of the 

 dorsum and the root, and are so arranged that they form a V, 

 the point of which is at the foramen caecum: 



The epithelium both of the upper and lower surfaces is 

 tesselated and laminar ; in the filiform papillae of the tongue 

 of adults the pavement cells are arranged in an imbricated 

 manner, and are provided with longer or shorter processes 

 which project freely beyond the papillae ; the most superficial 

 flattened and horny cells sometimes form solid hairs or fibres, 

 freely projecting beyond the secondary papillae. The epithelium 

 of the tongue is elsewhere similarly formed to that of other 

 parts of the oral cavity. 



The mucosa is thinner in the fore or horizontal part of the 

 tongue in Man, and is, at the same time, much more intimately 

 connected with the subjacent muscles than in the descending 

 portion, where, on account of the abundant loose submucous 

 tissue with numerous glands imbedded in it, it is easily mova- 

 ble; its elements are the same as those of the mucosa in other 

 parts of the oral cavity ; fibres of connective tissue being united 

 into fasciculi, and forming a close network that is connected 

 with the deeper tissues by strong trabeculae. 



The so-called septum cartilagineum of the human tongue, 

 which, arising from the hyoid bone, appears as a dense vertical 

 median plate situated between the Genio-glossi, and extending 

 through the whole length of the organ, gradually diminishing 



