THE ORAL CAVITY. 3 



upon the alveolar processes ; where, united into one mass with 

 the proper mucous membrane and the periosteum, it forms the 

 gums; upon the hard palate, to which the mucous membrane is 

 attached by an immoveable thick fibrous layer, which in some 

 parts contains glands; and finally upon the tongue where the 

 papillae are situated. In the latter case, there is a very close 

 union between the mucous membrane and the muscular tissue, 

 the processes of many muscular fibres extending into it and 

 terminating especially in a white, very solid, and dense, tendi- 

 nous layer, which is in immediate contiguity with the upper 

 longitudinal muscular fibres, and has been described as the fascia 

 lingua (Zaglas). 



With respect to the minute structure of the mucous mem- 

 brane of the mouth, connective tissue is the predominant 

 constituent of the submucous cellular tissue, while through- 

 out the proper mucous membrane, very numerous elastic 

 elements are everywhere found. In both localities, the former 

 usually presents itself in bundles of 0*002 — 0*005"' in breadth, 

 not united into a network, but while they cross one another in 

 the most various directions, presenting a certain indistinct 

 lamination. The felted mass of connective fibrils becomes 

 densest towards the epithelium, and finally passes into a more 

 structureless layer, which in my opinion is here, as little as in 

 the corium, to be considered a special membrane. In the inte- 

 rior of the papillce also, with the exception of those of the 

 tongue, a fibrous structure is usually very indistinct, the whole 

 more resembling a homogeneous substance, slightly granular. 

 The elastic element in the subcutaneous cellular tissue has 

 generally the form of scattered, interstitial, and occasionally, 

 though more rarely, of spirally convoluted, fine fibres; here and 

 there, as in the frenulum epiglottidis, they are not only more 

 abundant, but thicker. The latter is invariably the case in the 

 proper mucous membrane, which, even close to the epithelium, 

 contains in the midst of its connective tissue, very close and 

 intimately connected networks of elastic fibrils, or (and this is 

 the general rule) of moderately thick elastic fibres of 0*001 — 

 0*001 5 /// . Spirally convoluted elastic fibres exist here also, 

 though rarely. In addition, the mucous membrane contains 

 common fat-cells, sometimes in groups, sometimes more iso- 

 lated, and especially in the submucous layer. 



