222 BIRDS AND MAN 



species the set song has almost superseded the 

 plain single note, which has diminished to a 

 mere murmur ; in others, on the contrary, there 

 is no song at all, unless the single unvarying coo 

 can be called a song. In most species in the 

 typical genus Columba the plain coo is quite 

 distinct from the set song, but has at the same 

 time developed into a kind of second song, the 

 note being pleasantly modulated and repeated 

 many times. We find this in the rock -dove : 

 the curious guttural sounds composing its set 

 song, which accompany the love antics of the 

 male, are not musical, whUe the clear inflected 

 cooing note is agreeable to most ears. It is 

 a pleasing morning sound of the dove-cote ; but 

 the note, to be properly appreciated, must be 

 heard in some dimly Ughted ocean -cavern in 

 which the bird breeds in its wild state. The 

 long-drawn, oft -repeated musical coo mingles 

 with and is heard above the murmuring and 

 lapping of the water beneath; the hollow chamber 

 retains and prolongs the sound, and makes it 

 more sonorous, and at the same time gives it 

 something of mystery. 



Of aU the cooing notes of different species 



