106 WILD LIFE AT HOME. 



Gulls, like salmon and sea-trout, delight to 

 visit bodies of fresh water periodically, because it 

 has the very desirable effect of killing the parasites 

 living upon their bodies. At any time during the 

 summer two continual streams of sea-birds of 

 different species may be seen all day long crossing 



a piece of land dividing Loch Clift in Unst from 

 the sea. One stream represents birds going to 

 wash and the other those returning. After wash- 

 ing in the fresh water, the birds rise, shake them- 

 selves in mid-air, and retire to preen themselves, 

 facing the wind on a neighbouring hill-side ; and 

 the accompanying picture shows them in the act 

 of flying away. 



Two extremely interesting birds to study are 



