520 NERVOUS SYSTEM 



The sublingual may easily be exposed in the dog by making an 

 incision just below the border of the lower jaw, dissecting down to the 

 carotid artery and following the vessel upward until the nerve is seen 

 as it crosses its course. On applying a feeble faradic current at this 

 point, there are evidences of sensibility and the tongue is moved at 

 each stimulation. 



The phenomena following section of both sublingual nerves point 

 directly to their uses. The most notable fact observed after this 

 operation is that the movements of the tongue are lost, while general 

 sensibility and the sense of taste are not affected. The phenomena 

 following division of these nerves consist simply in loss of power over 

 the tongue, with considerable difficulty in deglutition. 



In the human subject the sublingual usually is more or less affected 

 in hemiplegia. In these cases, as the patient protrudes the tongue 

 the point is deviated. This is due to the unopposed action of the genio- 

 hyo-glossu-s on the sound side, which, as it protrudes the tongue, directs 

 the point toward the side affected with paralysis. 



