RAPIDITY OF FLIGHT. 99 



holds its neck and feet in a horizontal direction; 

 striking the upper column of air with its wings, then 

 raising and closing them one against the other above 

 its back, it darts on the flying-fish with such skill 

 and certainty, as almost invariably to ensure suc- 

 cess. 



Most travellers who have visited Constantinople, 

 by the passage of the Dardanelles and the Sea of 

 Marmora, may have noticed a bird not quite so 

 large as a Pigeon, abundant in that neighbourhood, 

 though occasionally seen in other parts of the Archi- 

 pelago, as at Napoli and Yourla, which must have 

 excited their curiosity and surprise. u Every day," 

 says one of the many authors who have noticed it, 

 " they are to be seen in numerous flocks, passing up 

 and down the Bosphorus with great rapidity. When 

 they arrive either at the Black Sea, or Sea of Mar- 

 mora, they again wheel about, and return up the 

 channel, and this course they continue, without a 

 moment's intermission, the whole day. They are 

 never seen to alight either on land or water; they 

 never for a moment deviate from their course, or 

 slacken their speed ; are never known to search for, 

 or take any food; and no visible cause can be 

 assigned for the extraordinary and restless instinct 

 by which they are haunted. They fly very near the 

 surface of the water; and if a boat meets a flock of 

 them, they either rise a few feet over it, or it 

 divides them like a wedge. Their flight is remark- 

 ably silent; and, though so numerous and so close, 

 the whirr of their wings is scarcely ever heard. 

 They are so abundant in the Sea of Marmora, that 

 near twenty flocks have been counted in a passage 



