66 THE GENESIS OF SPECIES. [CHAP 



and leaving offspring, but only an extra chance, the value 

 of which it is quite impossible to estimate." This difficulty 

 is, as Mr. Murphy points out, greatly intensified by the un- 

 doubted fact that the wonderfully complex structure has 

 been arrived at quite independently in beasts on the one 

 hand and in cuttle-fishes on the other ; while creatures of 

 the insect and crab division present us with a third and. 

 quite separately developed complexity. 



As to the ear, it would take up too much space to de- 

 scribe its internal structure ; 28 it must suffice to say that in 

 its interior there is an immense series of minute rod-like 

 bodies, termed fibres of Corti, having the appearance of a 

 key-board, and each fibre being connected with a filament 

 of the auditory nerve, these nerves being like strings to be 

 struck by the keys, i. e., by the fibres of Corti. Moreover, 

 this apparatus is supposed to be a key-board in function as 

 well as in appearance, the vibration of each one fibre giving 

 rise, it is believed, to the sensation of one particular tone, 

 and combinations of such vibrations producing chords. It 

 is by the action of this complex organ, then, that all the 

 wonderful intricacy and beauty of Beethoven and Mozart 

 come, most probably, to be perceived and appreciated. 



Now, it can hardly be contended that the preservation 

 of any race of men in the struggle for life ever depended 

 on such an extreme delicacy and refinement of the internal 

 ear a perfection only exercised in the enjoyment and ap- 

 preciation of the most perfect musical performances. How, 

 then, could either the minute incipient stages, or the final 

 perfecting touches of this admirable structure, have been 

 brought about by vague, aimless, and indefinite variations 

 in all conceivable directions of an organ, suitable to en- 

 able the rudest savage to minister to his necessities, but no 

 more ? 



28 The reader may consult Huxley's " Lessons in Elementary Physi- 

 ology," p. 204. 



