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 
hike 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 
esthetic feeling or taste in man, and deliberately 
