52 NATURAL HISTORY 



selves by rapid turns and quick evolutions; 

 swifts dash round in circles ; and the bank- 

 martin moves with frequent vacillations 

 like a butterfly. Most of the small birds 

 fly by jerks, rising and falling as they ad- 

 vance. Most small birds hop; butivagtails 

 and larks walk, moving their legs alter- 

 nately. Skylarks rise and fall perpendicu- 

 larly as they sing ; wood/arks hang poised 

 in the air; and titlarks rise and fall in large 

 curves, singing in their descent. The 

 white-throat uses odd jerks and gesticula- 

 tions over the tops of hedges and bushes. 

 All the duck- kind waddle; divers and auks 

 walk as if fettered, and stand erect on their 

 tails: these are the compedcs of Linnaus. 

 Geese and cranes, and most wild-fowls, move 

 in figured flights, often changing their 

 position. The secondary remiges of Trin- 

 gce, wild ducks, and some others, are very 

 long, and give their wings, when in motion, 

 an hooked appearance. Dab-chicks, moor- 

 hens, and coots, fly erect, with their legs 

 hanging down, and hardly make any dis- 



