THE EAR. 525 



very undesirable to have the basilar string in the ear vibrate 

 after the sound producing it has ceased. Short, sharp stac- 

 cato notes would be an impossibility and there would result 

 in the ear a blending and running together of sounds which 

 would preclude the possibility of fine music. For this rea- 

 son there are placed dampers on these strings, much after 

 the fashion of dampers on pianos. The rods of Corti seem 

 to have this function. Resting continually on the basilar 

 membrane they so weigh down these strings as to make 

 them cease their vibrations as soon as the force beneath 

 them producing the vibration has ceased. Just as in the 

 case of a piano the string is brought to quiet when the pedal 

 is on, as soon as the finger is taken from the key. 



Up to this point everything in connection with the ear 

 has been purely physical. It would happen in a dead ear 

 as readily as in a living one provided the tissues were left 

 intact, but there now remains the necessity for some kind of 

 an arrangement by means of which the vibrations of these 

 strings in the ear may be communicated to the brain. This 

 is accomplished by means of the auditory cells which stand 

 on the basilar membrane and which are directly connected 

 with the auditory nerve. 



When a certain string of the basilar membrane is set in 

 motion it is evident that the hair cells resting on it will be 

 moved up and down with it, and possibly this vibratory mo- 

 tion of the hair cells serves to originate a nervous impulse 

 which is then along the ordinary channels sent to the brain 

 and there interpreted as sound. 



A second possibility exists. The long stiff hairs which 

 are found projecting from the tops of these auditory cells 

 pass through little perforations in the recticular membrane, 

 and it may be that when these nervous cells move up and 

 down with the vibrations of the cord these delicate hairs are 

 rubbed against the recticular membrane and so produce a 

 friction which serves to originate a nervous impulse, which 

 then, as in the other case, finally gives rise to the percep- 

 tion of sound. That it must be either the movement of the 



