THE MUSICAL SENSE IN ANIMALS AND MEN. 353 



ing of the piano to sit by the player, and sometimes jumps into her 

 lap or on the key-board of the instrument. I know of a dog, too, 

 in a family in Berlin, which comes in in like manner when there is 

 music, often from distant rooms, opening the door with his paw. 

 I knew of another dog, usually thoroughly domestic, which occa- 

 sionally played the vagabond for love of music. Whenever the 

 semi-annual mass was celebrated in the city he could not be kept 

 at the house. As soon as the so-called Bergknappen, which were 

 accustomed to play at this time in the streets, appeared, he would 

 run away and follow them from morning till evening. 



Evidently neither cats nor dogs, nor other animals that listen 

 to human music, were constituted for the appreciation of it, for it 

 is not of the slightest use to them in the struggle for existence. 

 Moreover, they and their organs of hearing were much older than 

 man and his music. Their power of appreciating music is there- 

 fore an uncontemplated side-faculty of a hearing apparatus which 

 has become on other grounds what we find it to be. So it is, I 

 believe, with man. He has not acquired his musical hearing as 

 such, but has received a highly developed organ of hearing by a 

 process of selection, because it was necessary to him in the select- 

 ive process ; and this organ of hearing happens also to be adapted 

 to listening to music. 



It can not be said that this has been produced in man by nat- 

 ural breeding, or that it may not have been formed previous to 

 the human period. We know nothing of our direct predecessors ; 

 and, even if their remains should be found, the bony parts of the 

 organs of hearing in their skulls would furnish no clew to the 

 microscopic particulars of the soft parts with which they were 

 covered during life. It is, however, most probable that the pre- 

 cursors of man had nearly the same organs that he has now ; for 

 the living caricatures of men, the apes, have them in nearly the 

 same perfection. We have a right to assume this, although we 

 have not such detailed examinations of these organs as Hasse and 

 Retzius have given us of similar organs in other mammals. We 

 can not determine whether the compass of the scale audible to 

 apes is quite as large as that of men ; but we are authorized to 

 presume that it is about the same. The power of perceiving the 

 intervals between musical tones depends on a complicated appa- 

 ratus in the coil of the ear. This apparatus, called, after its dis- 

 coverer, the organ of Corti, includes thousands of nervous hair- 

 cells, each of which is excitable only by a single tone of definite 

 pitch. The delicacy of one's auditory apparatus — the correctness 

 of Helmholtz's interpretation of the significance of these organs 

 being presupposed — depends on the number of these hair-cells. 

 According to the exact measurements and enumerations of Ret- 

 zius, there are 15,500 of them in the ear of man, 12,500 in that of 



