THE EAR OF MAN. 221 



If proof were needed for the statement that most of 

 the speculation and experimentation on the auditory 

 function, especially as regards its different phases, has 

 led mostly to negative results, it is easily forthcoming ; 

 for there is not a single investigator who, during the 

 last half-century has written on this subject, but regrets 

 the paucity of facts and the depressing insufficiency 

 of the prevailing theories. 



The amount of experimental knowledge of the func- 

 tions of the lateral line organs is very limited indeed. 

 Of the many theories which have been proposed Merkel's 

 is by far the most satisfactory. According to this in- 

 vestigator, the function of these organs is in all proba- 

 bility that of receiving and transforming the mecJianical 

 stimuli occurring in the surrounding medium, and it 

 cannot be in any way connected with the perception 

 of chemical changes in the water. 



Mayser and Emery consider the organs of the lateral 

 line system as forming an accessory auditory organ, 

 and Mayser has proved that these organs find their 

 central brain connections in the immediate neighbor- 

 hood of the auditory nuclei. 



The functions of the ear are usually separated 

 into two classes by physiologists. The first and 

 most prominent of which is audition, with its several 

 subdivisions ; the second, though less prominent, not 

 for that reason, however, less important, viz. equilibra- 

 tion. The function of audition certainly belongs to 

 the ear ; not so, however the equilibrious function ; 

 for it can be conclusively shown that equilibration 

 is not necessarily affected by the removal of the ear, 

 and that injury to other organs is not unfrequently 



