8o THE SURGICAL ANATOMY OF THE HORSE 



parotid gland, since in the case under consideration the gland itself 

 may be detected apart from the swelling by carefully palpating its 

 outline. 



Owing to the natural difficulty which exists against the escape of 

 such material formed within the pouch (the communication with the 

 eustachian tube is in the form of a slit, and is situate at some distance 

 above the lowest level of the pouch), the affection usually runs a chronic 

 course, the liquid portion of the material is most frequently reabsorbed, 

 and the accumulations take a more or less solid consistency. This 

 consistency bears a close similarity to that of cartilage, and on this 

 account the name " chondroids " has been given to the ball-like masses 

 into which the inflammatory products so frequently resolve themselves. 



In some cases, however, the pouch may be found tightly distended 

 by material which retains the consistency of a thick liquid, and this 

 is frequently mixed with a quantity of food material which has found 

 its way into the pouch through the eustachian tube. 



A normal pouch when opened does not appear at all capacious, but 

 as an example of the great degree of distensibility possessed by the wall 

 of the pouch, it may be mentioned that Schlampp found as much as 

 twenty-seven ounces of food material accumulated in one pouch. 



It usually happens that one pouch only is affected, since there is 

 no direct communication between the two pouches. 



The cause of the affection remains, to a certain degree, in obscurity, 

 but cases of inflammation of the mucous lining of the pouch are generally 

 accorded to be due to an extension of a similar condition affecting the 

 mucous membrane of the pharynx. 



When the contents of the pouch are or a fluid consistency there 

 is present a discharge from one nostril, namelv, that of the side 

 corresponding to the pouch affected. This is due to the fact that 

 the opening of the eustachian tube is so disposed, that the material, 

 immediately on leaving the tube, readily passes into the posterior 

 meatus of that side. The discharge, moreover, differs from most 



