ORDER ACCIPITRES. 153 



assisted in their flight. The cold, which drives the birds of the 

 polar regions into more temperate climates, sends those of tem- 

 perate climates into the hot countries. But on the first indica- 

 tion of summer the hot climates send back to the temperate 

 their aerial inhabitants, and the temperate send back to the 

 cold regions their native tribes. Thus there is a general con- 

 centration of birds towards the torrid zone in winter, and a 

 general dispersion towards the poles in summer. 



The triangular figure which migrating birds adopt in their 

 flight is the most favourable for cutting through the air. The 

 bird placed at the point is the most fatigued of the entire band: 

 accordingly, each takes this place in turn. The migrations of 

 fishes are conducted in the same manner : the most robust 

 places himself at the head; the other males follow, and the 

 females and young come last. When the ranks of the storks 

 are broken by the wind, they condense into a circle. They do 

 the same when attacked by an eagle. 



Whatever the emigrations of birds may be, they yet do all 

 adopt a peculiar country. The palmipedes, such as the pen- 

 guins, the manchots, the petrel, the albatross, wild-goose, duck, 

 &c., prefer the northern climates and the polar seas. They are 

 entirely aquatic. The grallae, such as water-hens, colymbi, 

 herons, curlews, woodcocks, teal, storks, cranes, seek out 

 marshy places, covered, humid, and cold countries. These 

 are long-legged birds, and grope in the mud for prey*. They 

 do not bear extreme cold as well as the palmipedes, and conse- 

 quently they proceed further into the temperate regions. The 

 gallinacea inhabit the fields, dry ground, and even small hills^ 



* Nature, by a singular foresight, has imparted the faculty of sensatioa 

 to the extrcnnty of the beak of these birds', by means of a nervous branch 

 from the fifth pair which terminates there. This sensibiHty was necessary 

 to these races, because their sight could be of no assistance to them in 

 finding their prey in the mire. They are moreover inferior to other birda 

 in the acutencss of this last sense. 



