Chap, viii.] THE MOUTH. 101 



labialis). The free border of the lower lip is more 

 frequently the seat of epithelioma than is any other 

 part of the body. The lips contain a good deal of 

 connective tissue, and may swell to a considerable 

 size when inflamed, or cedematous. They are very 

 mobile, and are entirely free for a considerable extent 

 from bony attachment of any kind. It follows that 

 destructive inflammations of the lips, and such losses 

 of substance as accompany severe burns, produce much 

 contraction and deformity of the mouth. Contracting 

 cicatrices, also, in the vicinity of the mouth are apt 

 to drag upon the lips, everting them, or producing 

 kindred distortions. It is fortunate that the laxity of 

 the tissues around the mouth, and the general vascu- 

 larity of the part, greatly favour the success of the 

 many plastic operations performed to relieve these 

 deformities. 



The lips are very vascular, and are often the seat 

 of nsevi and other vascular tumours. The coronary 

 arteries are of large size, and their pulsations can 

 generally be felt when the lip is pinched up. These 

 vessels run beneath the orbicularis oris muscle, and 

 are consequently nearer to the mucous membrane than 

 they are to the skin. When the inner surface of the 

 lip is cut against the teeth, as the result of a blow, 

 these arteries are very apt to be wounded. As 

 such wounds are concealed from view the consequent 

 haemorrhage has sometimes given rise to an erroneous 

 diagnosis. Thus, Mr. Erichsen quotes the case of a 

 drunken man, the subject of such a wound, who, 

 having swallowed, and then vomited, the blood escap- 

 ing from a coronary artery, was for a while supposed 

 to be suffering from an internal injury. As the anas- 

 tomoses between the arteries of the lip are very free, 

 it is usually necessary to tie both ends of the vessel 

 when it has been cut across. 



The mucous glands in the submucous tissue are 



