86 THE BEAUTIES OF NATURE CHAP. 



another. It has been supposed that they 

 enable us to maintain the equilibrium of the 

 body, but no satisfactory explanation of their 

 function has yet been given. In the cochlea, 

 Corti discovered a remarkable organ consist- 

 ing of some four thousand complex arches, 

 which increase regularly in length and dimin- 

 ish in height. They are connected at one end 

 with the fibres of the auditory nerve, and 

 Helmholtz has suggested that the waves of 

 sound play on them, like the fingers of a per- 

 former on the keys of a piano, each separate 

 arch corresponding to a different sound. We 

 thus obtain a glimpse, though but a glimpse, 

 of the manner in which perhaps we hear ; but 

 when we pass on to the senses of smell and 

 taste, all we know is that the extreme nerve 

 fibres terminate in certain cells which differ 

 in form from those of the general surface ; 

 but in what manner the innumerable differ- 

 ences of taste or smell are communicated to 

 the brain, we are absolutely ignorant. 



If then v;o know so little about ourselves, 

 no wonder that with reference to other ani- 

 mals our ignorance is extreme. 



