DISEASES OF THE LIVEE. 401 



arises from the deep portion of the gland lying upon the hyo- 

 glossus muscle, deep to the mylo-hyoid. The duct runs forwards 

 and somewhat inwards, close beneath the mucous membrane of 

 the floor of the mouth, on which it makes a distinct ridge, to open 

 on a papilla by the side of the frsenum linguae. A calculus in this 

 duct can be easily palpated, or even seen, from within the mouth. 

 The duct is not readily dilated by retained secretion, and there- 

 fore its blockage by a concretion is apt to be accompanied by 

 much pain. Consequently a ranula is seldom a dilatation of this 

 duct, but is much more generally a retention cyst of one of the 

 mucous glands of the floor of the mouth. The calculus can be 

 easily excised by an incision made into the duct on the floor of 

 the mouth. 



The submandibular gland covers that part of the hyoglossus 

 muscle which overlies the lingual artery, and therefore it will 

 require displacing upwards to expose the lingual triangle formed 

 by the two portions of the intermediate tendon of digastric muscle 

 and the hypoglossal nerve. 



DISEASES OF THE LIVER. 



Deformities and Displacements. The deformity of the liver, 

 which is of most clinical interest, is the presence of a linguiform 

 lobe, known as Riedel's process. This is an elongated projection 

 which springs from the edge of the right lobe, close to the 

 gall bladder. In some instances it is congenital; in others it 

 appears to have been drawn down by the weight of a distended 

 gall bladder, which is attached to its deep surface. The lingui- 

 form lobe projects downwards in front of the right kidney, and 

 if its connexion with the liver escapes recognition it may be 

 confused with the kidney, a growth of the colon, or an intus- 

 susception. Biliary colic may exist with a linguiform lobe, owing 

 to traction on the bile duct. 



Various distortions of the liver are met with, as the result of 

 tight lacing and the use of tight belts, the precise deformity varies 

 with the level at which the compression is applied. 



C.A.A. 26 



