346 CLINICAL APPLIED ANATOMY. 



frequently on the lateral margin of the organ, and corresponds 

 to the position of a jagged bicuspid or molar, and it is here 

 again that epithelioma most frequently originates. 



The small ulcers seen upon the frsenum of the tongue in some 

 cases of whooping-cough may perhaps be explained by the 

 traction of this band of tissue across the two lower central 

 incisors during a paroxysm. 



Interstitial glossitis of a gummatous character is most com- 

 monly found in the middle line of the tongue towards the base, 

 which is possibly due to the fact that there is little if any 

 arterial anastomosis from one half of the tongue to the other, 

 the practically extra-vascular area permitting the development 

 of the infective granuloma and its subsequent caseation. 



Epithelioma of the Tongue. Unfortunately this is by no 

 means an infrequent disease, and a thorough knowledge of the 

 anatomical considerations concerning it is of the utmost impor- 

 tance in its early and radical treatment. 



The neoplasm commences as a rule in that part of the tongue 

 which is most subjected to irritation : hence, as has been men- 

 tioned, the side of the tongue is one of the most frequent sites. 

 The disease spreads locally in the substance of the organ, and if 

 left untouched, sooner or later involves the floor of the mouth 

 and subsequently the mandible. This local spread accounts for 

 the fixation of this naturally freely moveable organ, and when 

 the loss of mobility is well marked, and therefore protusion 

 greatly interfered with, the possibility of a complete extirpation 

 of the disease is extremely doubtful. 



The lymphatic glands are apt to be early enlarged. The sub- 

 mandibular and the deep carotid glands are those which are first 

 the sites of secondary deposits. The impossibility of determining 

 the actual implication of the glands in the early stages of the 

 disease renders it highly desirable, if not absolutely necessary, 

 that all the lymphatic nodes of the region should be dissected 

 out at the time of the operation upon the tongue, or very soon 

 afterwards. The submandibular glands lie in close connection 

 with, and even sometimes partially buried in, the submandibular 



