44 INTRODUCTION. 



from the populous north. When the weather grows dull, we 

 see passing through the misty air large detachments of Wood- 

 cocks, of Lapwings, and of Plovers : these are followed by trian- 

 gular bands of Cranes, Storks, of Teal, of Wild Geese, and Ducks. 

 They delight in inundated fields, or reedy marshes, or spread 

 themselves in the glades of humid and denuded woods. They 

 continually utter clamorous and melancholy cries, in accordance 

 with the bleak and wintry scene around them. It is a most 

 curious circumstance to observe that the Cranes leave and return 

 every year, with marvellous exactness, on the same days. 



The Palmipedes and G-rallcs come to us every winter from 

 the northern climates, whither they are driven by the ice, and 

 return in spring to their cold and humid habitations. The in- 

 sectivorous and granivorous races return with the flowers and 

 fine weather, from southern regions, to their native country, 

 allured by the expectation of renewed enjoyment and abundant 

 food. It is at the periods of the equinoxes that these great 

 voyages of birds are performed. These are also the periods of 

 great winds, as if nature had intended that the birds should be 

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

 the polar regions into more temperate climates, sends those of 

 temperate climates into the hot countries. But on the first indi- 

 cation 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 concentra- 

 tion 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 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 con- 

 ducted 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. Thus it appears that whatever the migra- 

 tions of birds may be, yet do they all adopt a peculiar country 

 each species has its distinct and never-varying habitat, where at 

 a particular period of the year it may certainly be found. In 

 the study of the natural history of the feathered tribes, it is of 

 great importance to remember this fact, and to note with exact- 

 ness the times and seasons of departure and return. Nothing is 

 more remarkable, nothing more truly wonderful in nature, than 

 the regularity and celerity of these annual migrations ; the im- 

 mense extent of illimitable space which the birds traverse, guided 

 only by an unerring instinct ; the intuitive knowledge whiclx 



