184 THE ANATOMY OP THE HORSE. 



it joins the submaxillary vein. Above the cheek it is continned as the 

 internal maxillary vein. 



Directions. — The buccinator muscle should be cut at its anterior 

 edge, and turned backwards so as to expose the interior of the cheek. 

 On the mucous membrane will be seen the following : — 



1. A linear series of small papillne opposite the upper molar teeth. 

 Each papilla is perforated at its summit by a duct from one of the 

 lobules of the superior buccal gland. 



2. A large rounded elevation opposite the third superior molar. 

 Stenson's duct opens on its summit. 



3. A linear series of small papillso opposite the inferior molars. Each 

 papilla is perforated by a duct from the inferior buccal gland. 



The Inferior Buccal Gland will be exposed by incising the mucous 

 membrane along the last-mentioned series of papilla?. It is composed 

 of a string of lobules included between the mucous membrane and the 

 buccinator. 



The Buccal Nerve wdll be found in close relation to the inferior 

 buccal gland. It is the sensory nerve to the cheek, and is derived from 

 the inferior maxillary division of the 5th cranial nerve. 



THE PTERYGO-MAXILLARY REGION AND THE REGION OF THE 

 GUTTURAL POUCH. 



Directions. — The outer surface of the inferior maxilla having been 

 laid bare from the condyle to the symphysis by the removal of the 

 muscles, the dissector is to make two sections with the saw. The first 

 is to be made obliquely from a jDoint about an inch above the last 

 molar tooth to the angle of the jaw ; the secOnd, close above the 

 symphysis. In making the sections, the edge of the saw must be kept 

 parallel to the surface of the bone, in order to avoid injury to the sub- 

 jacent structures. The jaw is next to be disarticulated by inserting a 

 strong scalpel into the joint ; and the scalpel is also to be pjissed round 

 the coronoid process, which Avill be felt embedded in the temporal 

 muscle, in the temporal fossa. The vertical ramus is now to be entirely 

 removed, at the same time leaving m position the parts beneath it. 

 This is to be done by raising the bone at the angle, and cutting the 

 muscular fibres inserted into its deep face. The edge of the knife is t(» 

 bo kept cutting on the bone, which is at the same time to be forcibly 

 tilted upwards and forwards until the coronoid process is torn out of 

 the temporal muscle. The horizontal ramus is next to be folded down- 

 wards and outwards ; and to permit this, it is only necessary to cut and 

 raise slightly the mucous membrane below the molar teeth. When these 

 operations have been effected, the dissection will take the form of Plate 

 30. The vertical ramus is to be retained to show the insertion of the 

 pterygoid and temporal muscles. 



