THE EAR OF MAN. 229 



which I briefly described to you at the beginning 

 of the hour. The auditory organ has played a long 

 and very important role in the phylogenetic history 

 of man. The auditory organ of man has no genetic 

 connection with any of the invertebrate auditory struc- 

 tures. 



At the PRESENT time the human ear is a canal organ 

 complexus, constructed according to a simple and sym- 

 metrical plan, whose ontogenetic history is a recapitula- 

 tion of many of the stages of its phylogeny. During its 

 development it is badly distorted, and the simplicity and 

 symmetry of the plan of its construction is thus in a 

 measure concealed. In its adult condition it is not the 

 most highly differentiated ear known to us, for some 

 other mammals are far more fortunate in this respect. 

 It is an organ about whose functions we know little, 

 since most of what is written in the text-books is pure 

 speculation, much of which is proven to be without 

 foundation, if, indeed, it is not directly controverted by 

 recent experiments. 



It subserves the auditory function, and has no more 

 to do with the equilibration of the body than many 

 other organs, especially those of the higher senses. 

 Its canals are not organs of equilibration. 



The FUTURE of the human ear can only be foreseen 

 in terms of its past and present. It will probably de- 

 velop functionally much more than structurally. Its 

 semicircular canals will gradually undergo reduction, 

 while its utricular and saccular complexes of sense- 

 organs will increase in size and perfection of structural 

 detail, in response to the increasing demands for tonal 



