192 DAEWINISM STATED BT DARWIN HIMSELF. 



that which is at first unpleasant to our senses, ultimately 

 becomes pleasant, and habits are inherited. 



DEVELOPMENT OE THE EAR FOE MUSIC. 



Descent ^ critic has asked how the ears of man, 



of Man, and he ought to have added of other animals, 

 ^^^^ ■ could have been adapted by selection so as 

 to distinguish musical notes. But this question shows 

 some confusion on the subject ; a noise is the sensation 

 resulting from the co-existence of several aerial "simple 

 vibrations" of various periods, each of which intermits 

 so frequently that its separate existence can not be per- 

 ceived. It ie only in the want of continuity of such 

 vibrations, and in their want of harmony inter se, that a 

 noise differs from a musical note. Thus an ear to be 

 capable of discriminating noises — and the high impor- 

 tance of this power to all animals is admitted by every 

 one — must be sensitive to musical notes. We have evi- 

 dence of this capacity even low down in the animal scale ; 

 thus crustaceans are provided with auditory hairs of dif- 

 ferent lengths, which have been seen to vibrate when the 

 proper musical notes are struck. As stated in a previous 

 chapter, similar observations have been made on the hairs 

 of the antennae of gnats. It has been positively asserted 

 by good observers that spiders are attracted by music. It 

 is also well known that some dogs howl when hearing 

 particular tones. Seals apparently appreciate music, and 

 their fondness for it " was well known to the ancients, 

 and is often taken advantage of by the hunters at the 

 present day." 



Therefore, as far as the mere perception of musical 

 notes is concerned, there seems no special difficulty in the 

 case of man or of any other animal. 



