SECONDARY SEXUAL CHARACTERS. 649 



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.^f 



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. Helmholtz has explained 

 on physiological principles why concords are agreeable and 

 discords disagreeable to the human ear; but we are little 

 concerned with these, as music in harmony is a late inven- 

 tion. We are more concerned with melody, and here 

 again, according to Helmholtz, it is intelligible why the 

 notes of our musical scale are used. The ear analyzes all 

 sounds into their component " simple vibrations," although 

 we are not conscious of this analysis. In a musical note 

 the lowest in pitch of these is generally predominant, and 

 the others which are less marked are the octave, the 

 twelfth, the second octave, etc., all harmonies of the 

 fundamental predominant note; any two notes of our scale 

 have many of these harmonic over-tones in common. It 

 seems pretty clear, then, that if an animal always wished 

 to sing precisely the same song, he would guide himself by 

 sounding those notes in succession which possess many 

 over-tones in common that is, he would choose for his 

 song notes which belong to our musical scale. 



But if it be further asked why musical tones in a certain 

 order and rhythm give man and other animals pleasure, we 

 can no more give the reason than for the pleasantness of 

 certain tastes and smells. That they do give pleasure of 

 some kind to animals we may infer from their being pro- 

 duced during the season of courtship by many insects, 

 spiders, fishes, amphibians and birds ; for unless the 

 females were able to appreciate such sounds and were 

 excited or charmed by them, the persevering efforts of the 

 males, and the complex structures often possessed by them 

 alone, would be useless ; and this it is impossible to 

 believe. 



* Several accounts have been published to tins effect. Mr. Peach 

 writes to me that be bas repeatedly found tbat an old dog of bis 

 bowls wben B flat is sounded on tbe flute, and to no other note. I 

 may add anotber instance of a dof^ always wbining, wben one note 

 on a concertina, wbich was out of tune, was played. 



f Mr. R. Brown, in ''Proc. Zool. Soc," 1868, p. 410. 



