The Nose, Mouth and Pharynx. 459 



of Wharton's duct, the outlet of the submaxillary gland. 

 The ducts of these salivary glands may become obstructed 

 by occlusion of their orifices or by salivary calculi, etc., 

 and when so occluded, there results a tumor which con- 

 tains a clear gelatinous fluid like the white of an egg. 

 When the tumor is caused by obstruction of the sublin- 

 gual ducts the swelling is most pronounced in the floor of 

 the mouth and beneath the chin ; but, when the submaxil- 

 lary duct is the one affected, then the swelling appears be- 

 neath the jaw at the side of the neck. 



The Hard Palate is covered by muco-periosteum, 

 and, when development is arrested, cleft palate results. 

 When operating for this condition, the incision into the 

 muco-periosteum should be made parallel and close to the 

 alveolar process, so as to include the main bloodvessel of 

 the hard palate, i.e., the descending palatine artery, in the 

 flap. When too free haemorrhage results from a wounded 

 posterior palatine artery, the canal, through which this 

 vessel emerges, may be plugged, if other means fail to 

 check the haemorrhage. This canal is situated close to 

 and on the inner side of the last molar tooth. 



On examining the fauces, the anterior pillars, form- 

 ed by the palato-glossi, are seen passing downwards and 

 forwards to the side of the tongue, while the posterior pil- 

 lars, passing downwards and backwards, are formed by 

 the palato-pharyngei muscles. In the triangle resulting 

 from the divergence of these elevations, is the tonsil. 



The Tonsil is, on an average, about half an inch in 

 diameter and one-third of an inch in thickness. It corre- 

 sponds to the angle of the jaw externally and is in rela- 

 tion with the ascending pharyngeal and the internal caro- 

 tid arteries, the former in front of the latter. The tonsil 

 is separated from these vessels by the superior constric- 

 tor and the pharyngeal aponeurosis, only, so that they 



