230 NA TURA L HIS TOR Y OF SELB ORNE. 



ground and water, and distinguish themselves 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 advance. Most small 

 birds hop ; but wagtails and larks walk, moving their legs alter- 

 nately. Skylarks rise and fall perpendicularly as they sing ; 

 woodlarks hang poised in the air ; and tit-larks rise and fall in 

 large curves, singing in their descent. The white-throat uses odd 

 jerks and gesticulations 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 compedes of Linnaeus. 

 Geese and cranes, and most wild fowls, move in figured flights, 

 often changing their position. The secondary remiges of Tringac, 

 wild ducks, and some others, are very long, and give their wings, 

 when in motion, an hooked appearance. Dabchicks, moor-hens, 

 and coots, fly erect, with their legs hanging down, and hardly make 

 any dispatch ; the reason is plain, their wings are placed too 

 forward out of the true centre of gravity ; as the legs of auks and 

 divers are situated too backward. 



