CH. VI. ROCK-PIGEONS. 85 



and is seen again issuing from the rocks within 

 this cavern, through which it runs for a short 

 distance till it empties itself into the sea. 



Numbers of the common house martin were fly- 

 ing about the cave, and building their nests in the 

 niches of the rocks. In some of the dark, damp 

 corners, where there seems to be a constant dripping 

 from the roof, were clusters of bright green ferns, 

 and other plants, in great variety. On some parts 

 of the shore the rocks are quite perpendicular for 

 a great height I should say about three hundred 

 feet; in others they are worn into numerous fantastic 

 shapes and caverns by the action of the waves. 



Although the wind had now fallen, the swell 

 was tremendous, dashing the spray half-way up 

 the rocks. It was a curious sight to see the 

 rock-pigeons flying rapidly into the caves, some- 

 times dashing like lightning through the very 

 spray of the breakers, scarcely topping the crests 

 of the waves, which roared and raged through the 

 narrow caverns where these beautiful birds breed. 

 The rock-pigeons were very numerous here, and 

 constantly flying between their wild but secure 

 breeding-places and the small fields about Durness. 

 I shot a few of them, and found their crops full 

 of green food, such- as clover, the leaves of the oat, 

 etc. ; a number of small shells were also in the 



