ROCK AND RIVER OUSELS. 285 



on the stone to keep up the deception, and, generally before 

 commencing operations, you see the duck's head fly off. I 

 have noticed this bird with a large worm in its beak, which 

 it had picked out of the banks of a mossy brook, high among 

 the hills, its summer residence. During the severity of winter 

 it always prefers larger streams, its favourite food being the 

 spawn of fish and water-insects. 



