132 BIRDS AND MAN 



and coarse, the tones of sympathy and refinement 

 are relatively gentle and of agreeable timbre. 

 That is to say, the timbre is associated in experi- 

 ence with the receipt of gratification, has acquired 

 a pleasure-giving quality, and consequently the 

 tones which in music have an allied timbre become 

 pleasure-giving and are called beautiful. Not 

 that this is the sole cause of their pleasure-giving 

 quality. . . . Still, in recalling the tones of in- 

 struments which approach the tones of the human 

 voice, and observing that they seem beautiful in 

 proportion to their approach, we see that this 

 secondary aesthetic element is important." 



As with instruments, so it is with bird voices ; 

 in proportion as they approach the tones of the 

 human voice, expressive of sympathy, refinement, 

 and other beautiful qualities, they will seem beauti- 

 ful in some cases even more beautiful than those 

 which, however high they may rank in other ways, 

 are yet without this secondary aesthetic element. 



