PETRELS. 



311 



a gale, coursing over the waves, down the declivi- 

 ties, up the ascents of the foaming surf that 

 threatens to burst over their heads, sweeping along 

 the hollow troughs of the sea, as in a sheltered 







WILSON'S PETREL. 



valley, and again mounting with the rising billow, 

 and just above its surface, occasionally dropping 

 its feet, which striking the water throws it up 

 again with additional force, sometimes leaping 

 with both legs parallel, on the surface of the 

 roughest waves for several yards at a time* Mean- 

 while, it continues coursing from side to side of 

 the ship's wake, making excursions far and wide, 



