\ \KII.TY OF BONG 121 



slowly <>i- rapidly as I lie C8S6 may be, whilst at 

 the other we have the complex productions 

 of the Warblers; and between these two 

 extremes, notes and phrases are combined and 



mbined in ways innumerable. And just as 

 there is a rich variety of combination, so 

 there is a very wide variation in the purity 

 and character of the notes some are harsh, 

 others melodious, some flute-like, others more 

 of a whistle, and others again such as can 

 only be likened to the notes of a stringed 

 instrument. Hence in variety of phrase com- 

 bination added to variety in the character of 

 the note, there is a possibility of infinite modes 

 of expression. 



If, in the latter part of May, we take up 

 a position at dawn in some osier bed, we listen 

 to songs which have reached a high degree 

 of specialisation, songs, moreover, which appeal 

 to us on account of their beauty ; if, on the 

 other hand, we climb down the face of the 

 sea cliff, we hear an entirely different class of 

 songs harsh, guttural, weird, monotonous 

 sounds, which, appeal to us though they may, 

 lack the music of the voices in the osier bed. 

 And just as, in the osier bed, we can recognise 

 each species by its voice, so we can distinguish 

 the "cackle" of the Fulmar, the "croak" of 

 the Guillemot, or the "grunt" of the Shag. 

 In the osier bed, however, there is considerable 

 variation in the song of different individuals 

 of the same species, so much so that we can 

 recognise this one from that ; whereas on the 



