THE GUTTURAL POUCHES 79 



bone in front, and the elevation which indicates the inferior extremity 

 of the styloid process of the occipital bone, behind. 



If a longitudinal section of the head be prepared and an incision 

 made into the pouch through its inner wall, by the introduction of a 

 finger into the cavity of the pouch, and by insinuating it in the forward 

 direction, it will be found that the pouch becomes much narrowed down 

 towards its anterior extremity. Here it forms a kind of diverticulum 

 which comes into close relationship with the posterior wall of the 

 pharynx. This diverticulum extends downwards and forwards in the 

 direction of the long axis of the poach. There is also a posterior 

 diverticulum, which has already been referred to as extending 

 downwards in the direction of the angle of the jaw. 



These are points of considerable clinical importance ; for in cases 

 of accumulation of inflammatory or other products in the pouch, it will be 

 evident that these products will gravitate downwards and forwards into 

 the anterior diverticulum, and since there is little resistance to the 

 pressure caused by the products the pouch is distended and bulges 

 prominently into the pharynx, so prominently in fact that there is 

 marked interference with the respirations of the animal, which become 

 quite audible. 



Again, since the floor of tlie pouch is in immediate relationship to 

 the pharyngeal opening of the oesophagus, the pressure upon this opening 

 renders the acts of deglutition much more difficult. There is also much 

 soreness evinced when the region of the throat is pressed from without. 



The products also gravitate into the posterior diverticulum, but in 

 this direction their downward movement meets with considerable 

 resistance, owing to the proximity of the ramus of the inferior maxillary 

 bone. As the condition progresses therefore the accumulating matter 

 becomes pressed in the direction of least resistance, and on this account 

 a well-marked external distension ultimately makes its appearance, which 

 is most apparent immediately in front ot the wing of the atlas. 



This swelling may be differentiated from an enlargement of the 



