Music and Dancing in Nature. 271 
between male and female, composed of impetuous and 
more or less confused notes and screams, accom- 
panied with beating of wings and other gestures. 
In some species choruses take the place of duets, 
while in others entirely different forms of display 
have been developed. In one group—Cnipolegus— 
the male indulges in solitary antics, while the silent, 
modest-coloured female keeps in hiding. Thus, the 
male of Cnipolegus Hudsoni, an intensely black- 
plumaged species with a concealed white wing-band, 
takes his stand on a dead twig on the summit of a 
bush. At intervals he leaves his perch, displaying 
the intense white on the quills, and producing, as 
the wings are thrown open and shut alternately, 
the effect of successive flashes of light. Then sud- 
denly the bird begins revolving in the air about its 
perch, like a moth wheeling round and close to the 
flame of a candle, emitting a series of sharp clicks 
and making a loud humming with the wings. 
While performing this aérial waltz the black and 
white on the quills mix, the wings appearing like a 
grey mist encircling the body. The fantastic dance 
over, the bird drops suddenly on to its perch 
again ; and, until moved to another display, remains 
as stiff and motionless as a bird carved out of jet. 
The performance of the scissors-tail, another 
tyrant-bird, is also remarkable. ‘This species is 
grey and white, with black head and tail and a 
crocus-yellow crest. On the wing it looks like a 
large swallow, but with the two outer tail-feathers 
a foot long. ‘The scissors-tails always live in pairs, 
but at sunset several pairs assemble, the birds 
calling excitedly to each other ; they then mount 
