504 THE INTESTINAL CANAL, BY E. KLEIN AND E. VERSON. 



Steno's duct opens they also form a series of glands known as 

 the glandules molares * According to Ward, they are from two 

 to four in number, are situated between the masseter and bucci- 

 nator muscles, and are larger and composed of more lobules 

 than the remaining glands of the oral mucous membrane. 



At the point where the lips are reflected upon the anterior 

 surface of the jaws, the mucous membrane at the middle line, 

 both above and below, forms a small duplicature, termed the 

 frcenum. 



The epithelium of the mucous membrane is here thinner than 

 elsewhere ; the papillae are also smaller and less numerous ; the 

 mucosa itself is not distinguishable. The vessels are relatively 

 numerous, and it contains a considerable number of fine irre- 

 gularly coursing elastic fibres. 



That portion of the mucous membrane which covers the 

 alveolar processes of the jaw, and surrounds the necks of the 

 teeth, passing anteriorly into the mucous membrane of the 

 lips, posteriorly at the root of the oral cavity into that of the 

 hard palate, and below into that of the floor of the mouth, is 

 named the gum (Gingiva). 



The gum, on account of the abundance of tendinous fasciculi 

 it contains, is denser and tougher than the mucous membrane 

 of any other part of the mouth ; it is intimately adherent to 

 the bone in consequence of the direct prolongation of the ten- 

 dinous fasciculi of the periosteum into the mucosa. 



The epithelium of the gum is composed of laminae of tesse- 

 lated cells, amongst which are exceedingly well-marked ribbed 

 cells. The superficial cells are strongly flattened ; those more 

 deeply situated become thicker, and possess strongly defined 

 ribs. The deepest cells are cylindrical, with conical external 

 extremities. 



The papillce of the mucosa of the gum are all relatively 

 broad at their bases, of unequal height, with conical or rounded 

 external extremities, which are sometimes simple and sometimes 

 divided. 



The tissue of the mucosa is tough, and is composed of broad 



* N. Ward, art. " Salivary Glands," in Todd's Cyclopcedia of Anatomy 

 and Physiology, Vol. ii., p. 422. 



