52 NATURAL HISTORY 



sevles by rapid turns and quick evolutions ; 

 swifts dash round in circles ; and the hank- 

 martin moves w^ith frequent vacillations 

 like a butterfly. Most of the small birds 

 fly by jerks, rising and falling as they ad- 

 vance. Most small birds hop ; but wagtails 

 and larks walk, moving their legs alter- 

 nately. Skylarks rise and fall perpendicu- 

 larly as they sing ; woodlarks 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 duek'kind waddle ; divers and auks 

 walk as if fettered, and stand erect on their 

 tails : these are the cowpedes of Linn(Bus. 

 Geese and cranes, and most wild-fowls, move 

 in figured flights, often changing their 

 position. The secondary remiges of Trin^ 

 g(E, 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- 



