26 INTRODUCTION. 



We shall not here enter into any detailed description of the man- 

 ner in which each species conducts its migration ; but shall con- 

 tent ourselves with citing the single remarkable example of the 

 motions of the Cranes. Of all migrating birds, these appear to be 

 endowed with the greatest share of foresight. They never under- 

 take the journey alone : throughout a circle of several miles, they 

 appear to communicate the intention of commencing their route. 

 Several days previous to their departure, they call upon each other 

 by a peculiar cry, as if giving warning to assemble at a cen- 

 tral point; the favorable moment being at length arrived, they 

 betake themselves to flight, and, in military style, fall into two 

 lines, which, uniting at the summit, form an extended angle with 

 two equal sides. At the central point of the phalanx, the chief 

 takes his station, to whom the whole troop, by their subordination, 

 appear to have pledged their obedience. The commander has not 

 only the painful task of breaking the path through the air, but he 

 has also the charge of watching for the common safety ; to avoid 

 tlie attacks of birds of prey; lo range the two lines in a circle, at 

 the approach of a tempest, in order to resist with more effect the 

 squalls which menace the dispersion of the linear ranks; and, lastly, 

 it is to their leader that the fatigued company look up to appoint 

 the most convenient places for nourishment and repose. Still, im- 

 portant as is the station and function of the aerial director, its 

 existence is but momentary. As soon as he feels sensible of fatigue, 

 he cedes his place to the next in the file, and retires himself to its 

 extremity. During the night, their flight is attended with con- 

 siderable noise ; the loud cries which we hear, seem to be the march- 

 ing orders of the chief, answered by the ranks who follow his 

 commands. Wild Geese, and several kinds of Ducks, also make 

 their aerial voyage nearly in the same manner as the Cranes. The 

 loud call of tlie passing Geese, as they soar securely through the 

 higher regions of the air, is familiar to all ; but as an additional 

 proof of their sagacity and caution, we may remark, that when 

 fogs in the atmosphere render their flight necessarily low, they steal 

 along in silence, as if aware of the danger to which their lower path 

 now exposes them. 



To assist the efforts of birds, and sustain them through their long 

 journeys, it is often necessary to borrow the aid of the winds ; but 

 that this element may assist, it is proper that it meet them ; or be 

 in the reverse of its aid to the navigator. This observation is so 

 far verified, that to succeed in the chase of birds upon the water, it 



