THKIFT-HILLOCKS. 31 



wings and elegant sailing flight. They are wary and 

 alert ; we do not see them sitting still as we approach, 

 as the puffins and razor-bills do, for before we can get 

 within gun-range they are on the wing. Then, as 

 conscious of their powers, they are bold ; sweeping by 

 over our heads, with a querulous scream ; now and 

 then swooping down and making as if they would dash 

 at our faces, but taking care to swerve as they come 

 close, and gliding away with the most graceful ease 

 and freedom. 



Let us examine for a moment the ground beneath 

 our feet. We need caution in moving about, for the 

 tussocks and mounds feel precariously hollow and 

 spongy ; now and then the foot breaks through, and 

 the whole leg is buried in a dusty cavity that gives 

 forth an insufferable odour of guano ; then as we 

 jump on a hillock, it totters and breaks off from its 

 base to roll down the hill, laying bare an interior 

 riddled with holes like a honeycomb. These hillocks 

 themselves are nothing but enormous tufts of the 

 common thrift or sea-lavender, so often used for 

 edgings in cottage gardens : the plant in a succession 

 of years assumes a dense hemispherical form, while 

 the decay of the old leaves forms a reddish spongy 

 earth, which constantly accumulates, and constitutes 

 the soil on which the living plant grows. 



Under the projecting shelter of one of these tussocks 

 we found a nest of one of the gulls, the lesser black- 

 backed species as was supposed. It was a platform 

 made of the red leaf-bases of the thrift, dry and brittle, 



