Music and Dancing in Nature. 263 



him that these little creatures were known as the 

 " dancing birds." 



This species was probably solitary, except when 

 assembling for the purpose of display; but in a 

 majority of cases, especially in the Passerine order, 

 the solitary species performs its antics alone, or 

 with no witness but its mate. Azara, describing a 

 small finch, which he aptly named Oscilador, says 

 that early and late in the day it mounts up vertically 

 to a moderate height ; then flies off to a distance 

 of twenty yards, describing a perfect curve in its 

 passage ; turning, it flies back over the imaginary 

 line it has traced, and so on repeatedly, appearing 

 like a pendulum swung in space by an invisible 

 thread. 



Those who seek to know the cause and origin of 

 this kind of display and of song in animals are re- 

 ferred to Darwin's Descent of Man for an explanation. 

 The greater part of that work is occupied with a 

 laborious argument intended to prove that the love- 

 feeling inspires the animals engaged in these ex- 

 hibitions, and that sexual selection, or the voluntary 

 selection of mates by the females, is the final cause 

 of all set musical and dancing performances, as well 

 as of bright and harmonious colouring, and of 

 ornaments. 



The theory, with regard to birds is, that in the 

 love-season, when the males are excited and engage 

 in courtship, the females do not fall to the strongest 

 and most active, nor to those that are first in the 

 field ; but that in a large number of species they 

 are endowed with a faculty corresponding to the 

 aesthetic feeling or taste in man, and deliberately 



