SENSATIONS OF TASTE AND SMELL. 



271 



pharyngeal reach the same ganglion through the nerve of Jacobson, 

 the small superficial petrosal, and the otic ganglion. A recent re- 

 port by Cushing,* of the results of removal of the Gasserian gan- 

 glion in thirteen cases, throws much doubt upon these views. This 

 author made careful examinations of the sense of taste, not only 

 immediately after the operation, but for a long period subsequently. 

 He states that in no case was there any effect upon the sense of taste 

 in the posterior third of the tongue. We may believe, therefore, that 

 the taste fibers of this part arise immediately from the ganglion 

 cells in the petrosal ganglion and enter the brain with the roots of 

 the nerve to terminate in its sensory nucleus in the medulla. Regard- 



^ptftos.swptffitxoli 



^eTrosum.X'i 



"S^eus 



Fig. 113- Schema to show the course of the taste fibers from tongue to brain. 

 (.Cushing.) The dotted lines represent the course as indicated by Cushing's observations. 

 The full black lines indicate the paths by which some authors have supposed that these 

 -fibers enter the brain in the trigeminal nerve. 



ing the anterior two-thirds of the tongue, the lingual region, it was 

 found that in some cases there was at first a loss of acuity of taste 

 or even an entire disappearance of the sense, but subsequently 

 it returned. It would seem, therefore, that the loss of taste de- 

 scribed after removal of the Gasserian ganglion is an incidental 

 result the cause of which is not entirely clear. Cushing attributes 

 it to a postoperative degeneration and swelling in the fibers of the 

 lingual nerve, which affect the conductivity of the intermingled 

 fibers of the chorda tympani. Since, however, there is no perma- 



* Cushing, " Bulletin of the Johns Hopkins Hospital," 14, 71, 1903. Gives 

 also the surgical literature. 



