NOTICEABLE INCIDENTS 73 



I o. Accent in song. Many species, and especially 

 the brown wren, hedge-accentor, thrush, and blackcap, 

 accentuate certain notes in their songs, thus producing 

 a rhythmical progression throughout the phrase. The 

 blackbird often exhibits the same feature. 



1 1 . Birds which sing well and continuously are 

 generally clad in sober hues ; and the converse is 

 equally true, namely, that brightly coloured birds 

 are not singers. There are, of course, some well- 

 known exceptions such as the American bluebird, 

 our own goldfinch, and the great titmouse. If, as 

 appears to be the case, brightly coloured birds and 

 singing -birds have been developed from common 

 types, there must have been some cause for this 

 divorcement of colour from song in the avian races. 

 Is it not probable that, just as some female birds may 

 have been influenced by the songs of their suitors, 

 so others may have been similarly affected by the 

 brightness of hues which certain males may have 

 displayed ; and also that as arboreal birds may have 

 developed a great sensitiveness of hearing by 

 listening to the notes of others hidden from them by 

 leaves, so other birds, from specially exercising the 

 eyes for a similar purpose, may have developed a 

 habit of scrutinising every object very intently, and 

 thus have been induced, all unconsciously, to prefer 



