MIGRATION AND FLIGHT. 109 



wings, or the shrill notes of call, by which these vast 

 flights are kept together in the darkness of night, 

 may he heard over head. 



Birds, too, in their longer flights, no doubt avail 

 themselves of different currents in the air ; for we 

 know that often, when the lower stream of air is 

 blowing from the west, another stream, far above, 

 may be blowing from another direction; this maybe 

 frequently seen by the motion of the upper clouds 

 moving in contrary directions from those at a lower 

 level. Those most beautiful of all the feathered 

 race, the Birds of Paradise, (not only distinguished 

 by their brilliant plumage, but from their being 

 singularly decorated with tufts or trains of light 

 loose fringy feathers, which render it difficult for 

 them to fly, excepting against the wind, which 

 smooths them down,) are chiefly natives of a; few 

 islands in the Indian Ocean ; and when sailing 

 between these islands, flocks of them are often seen 

 crossing, and always flying against the wind : but 

 as, in that climate, sudden squalls often occur from 

 an opposite quarter, the birds, when caught by them, 

 are observed immediately to dart upwards till they 

 ascend beyond the reach of the gale, and are then 

 seen to pursue their course as before. 



One other very remarable fact connected with 

 these long journeys, undertaken by birds over seas 

 and lands, is, that they are gifted with some secret 

 power, enabling them not only to find their way to 

 and from the distant countries they visit, but ac- 

 tually guiding them to the very same places from 

 whence they came, and the very same spots for 



