q8 DARWINISM AND THE PROBLEMS OF LIFE 



lady of the district has a spouse. Nevertheless, this 

 suggestion must not prevent us from confessing candidly 

 that we have as yet no satisfactory explanation of the 

 complicated song of the bird. 



And how the songs of the birds differ! The 

 monotonous " delm, dilm, delm, dilm " of the willow- 

 wren, the rolling flute-like song of the hedge-sparrow, 

 the strong exulting note of the chaffinch, the rippling 

 song of the black-cap with its bell-like ending, the 

 melancholic, varied tones of the song-thrush, and the 

 indescribable song of the nightingale; what variety in 

 the fulness of tone, in the change of the notes, in the 

 rhythm ! 



Birds not only sing, but many of them play a very 

 peculiar instrumental music. Storks clap with their beaks, 

 bitterns pump their gullet full of air and give out the 

 powerful bellow that has frightened many a traveller. 

 The spotted wood-pecker and its black companion fasten 

 themselves on the branch of a tree, and with rapid 

 stroke of the beak, helped by the vibration of the branch, 

 send a humming rattle through the wood. Those who 

 go through damp meadows in the spring hear a 

 mysterious tone like that of a hautboy vibrating through 

 the twilight. This is caused by the snipes, whose tail- 

 feathers are set in vibration by the air like the tongues 

 of a reed-instrument, as the bird is descending, and with 

 a peculiar quiver in its wings sends a current of air 

 through them. 



Some birds are able to imitate the sounds of others. 

 The jay is a great artist at this work. This pretty 

 but thievish bird, with its fine blue epaulettes, often 



