7 he Nose, Mouth and Phatynx. 457 



by the posterior fibres of the genio-hyo-glossus. These 

 actions are assisted by the muscles steadying the hyoid 

 bone, viz., by the stylo-hyoid, both bellies of the digas- 

 tric, mylo-hyoid and the genio-hyoid. 



Operations. Division of the fr&num lingutz. 

 In this operation the blunt-pointed, curved scissors are 

 directed towards the symphysis, since, if they were direct- 

 ed horizontally towards the tongue, the ranine artery 

 might be wounded. 



Division of the lingual branch of the inferior maxil- 

 lary. This sensory nerve passes forwards to the side of 

 the tongue, lying below and behind the last molar tooth. 

 It can be divided by making an incision at a point, about 

 half an inch below and behind the tooth, or by incising 

 over the nerve as it lies by the side of the tongue. If the 

 surgeon draw the protruded tongue towards the opposite 

 side, the nerve may be identified, since it causes the mu- 

 cous membrane to become elevated, ridge-like, opposite 

 the second molar tooth, and, on division of this membrane, 

 the nerve is exposed, when it can be divided or exsected 

 if necessary. Its division may be desirable in cancer of 

 the tongue in which the pain is intense. Excision of the 

 tongue. It must be remembered, that in cases of malig- 

 nant disease of the tongue, in which one side only is in- 

 volved, this side may be readily removed, and, if there 

 have been preliminary ligation of the lingual artery, haem- 

 orrhage need not be feared, since the anastomosis be- 

 tween the bloodvessels on either side of the septum linguae 

 is capillary only and very limited at that. Treves is of the 

 opinion that the complete excision is preferable to a par- 

 tial operation, even though one side, only, is affected, and 

 he advises excision through the mouth, after ligating both 

 linguals. When, however, it is necessary to remove the 

 entire tongue, it will render the prognosis better if the 



