chap, v.] THE EAR. 69 



passes between the patient's meatus and his own. Pro- 

 longed closure of the Eustachian tube leads to deaf- 

 ness, and thus impairment of hearing may follow upon 

 great thickening of the mucous membrane of the tube 

 due to the extension of inflammatory mischief from 

 the pharynx. In the deafness associated with enlarged 

 tonsils, the hypertrophic change extends to the mucous 

 lining of the tube, and in the cases of many pharyngeal 

 growths and nasal polypi, the orifice of the tube is 

 mechanically obstructed. The near relation of the 

 pharyngeal end of the tube to the posterior nares 

 serves to explain a case where suppuration in the rnas- 

 toid cells followed upon plugging of the nares for 

 epistaxis. A probe passed up the Eustachian tube 

 from the pharynx would hit the joint between the 

 incus and the stapes, arid would then enter the mastoid 

 cells (Tillaux). 



The upper edge of the pharyngeal orifice of the 

 tube is about half an inch below the basilar process, 

 half an inch in front of the posterior wall of the 

 pharynx, half an inch behind the posterior end of 

 the inferior turbinated bone, and half an inch above 

 the soft palate (Tillaux). 



Just behind the elevation formed at the orifice of 

 the Eustachian tube, there is a depression in the wall 

 of the pharynx, known as the fossa of Rosenmuller. 

 It may be mistaken for the orifice of the tube, and 

 may readily engage the point of an Eustachian 

 catheter. To pass the Eustachian catheter, the in- 

 strument is carried along the floor of the nares with 

 its concavity downwards, " until its point can be felt 

 to drop over the posterior edge of the hard palate 

 into the pharynx. The instrument should now be 

 withdrawn until its point can be felt to rise again on 

 the posterior edge of the hard palate; having arrived 

 at this point, the catheter should be pushed onwards 

 about one inch, and during its passage its point should 



