Music and Dancing in Nature. 265 



the Chinchillidae family, have greatly developed 

 vocal organs, and resemble birds in loquacity ; but 

 mammals generally, compared with birds, are slow 

 and heavy, and not so readily moved to exhibitions 

 of the kind I am discussing. 



The terrestrial dances, often very elaborate, of 

 heavy birds, like those of the gallinaceous kind, are 

 represented in the more volatile species by per- 

 formances in the air, and these are very much more 

 beautiful ; while a very large number of birds — 

 hawks, vultures, swifts, swallows, nightjars, storks, 

 ibises, spoonbills, and gulls — circle about in the 

 air, singly or in flocks. Sometimes, in serene 

 weather, they rise to a vast altitude, and float about 

 in one spot for an hour or longer at a stretch, 

 showing a faint bird-cloud in the blue, that does 

 not change its form, nor grow lighter and denser 

 like a flock of starlings ; but in the seeming con- 

 fusion there is perfect order, and amidst many 

 hundreds each swift- or slow-gliding figure keeps 

 its proper distance with such exactitude that no 

 two ever touch, even with the extremity of the long 

 wings, flapping or motionless : — such a multitude, 

 and such miraculous precision in the endless curving 

 motions of all the members of it, that the spectator 

 can lie for an hour on his back without weariness 

 watching this mystic cloud-dance in the empyrean. 



The black-faced ibis of Patagonia, a bird nearly 

 as large as a turkey, indulges in a curious mad 

 performance, usually in the evening when feeding- 

 time is over. The birds of a flock, while winging 

 their way to the roosting-place, all at once seem 

 possessed with frenzy, simultaneously dashing 



