THE EAR OF MAN. 22/ 



the removal of the ear from the surface of the body, 

 and is greatly increased as soon as the forms emerge 

 into the poorer conducting medium of the aerial 



ocean. 



When the structure of the internal ear of the higher 

 vertebrate has been analyzed with reference to deter- 

 minins: its functions, we find that it is easilv reduced 

 to the type of the canal organ on the surface of the 

 body, and we should expect an essential harmony be- 

 tween the functions of these two groups of organs, 

 although in the case of the ear the functions would 

 necessarily be in some degree modified to correspond 

 with its modifications of structure. These latter, we 

 know, have not been extensive, except in the case 

 of the cochlea, and, strange as it may seem, we are 

 not able to assign to the cochlea any function at all 

 in keeping with the great complication of structure 

 which it has undergone during its evolution from the 

 lagena. 



The Helmholtz piano-string theory is entirely in- 

 adequate to account for perception of musical tones 

 by vertebrate animals, in that it can be ai^plied only 

 to the higher mammalian forms, and leaves us to seek 

 another explanation for the equal, if not greater, powers 

 of musical perception possessed by some birds. What- 

 ever explanation future investigation may disclose to 

 us, it is safe to say that it will prove equally applicable 

 to all vertebrate forms capable of musical perception, 

 while being in perfect harmony with the then' per- 

 fected knowledge of sound (tone) perception by means 

 of lateral line organs. 



