262 The Naturalist in La Plata. 
begins a series of movements as if dancing a 
minuet ; finally, carried away with excitement, he 
leaps and gyrates in the most astonishing manner, 
until, becoming exhausted, he retires, and another 
bird takes his place. 
In other species all the birds in a company unite 
in the set performances, and seem to obey an impulse 
which affects them simultaneously and in the same 
degree ; but sometimes one bird prompts the others 
and takes a principal part. One of the most curious 
instances I have come across in reading is contained 
in Mr. Bige-Wither’s Pioneering im South Brazil. 
He relates that one morning in the dense forest 
his attention was roused by the unwonted sound 
of a bird singing—songsters being rare in that 
district. His men, immediately they caught the 
sound, invited him to follow them, hinting that he 
would probably witness a very curious sight. 
Cautiously making their way through the dense 
undergrowth, they finally came in sight of a small 
stony spot of ground, at the end of a tiny glade; 
aud on this spot, some on the stone and some on 
the shrubs, were assembled a number of little birds, 
about the size of tom-tits, with lovely blue plumage 
and red top-knots. One was perched quite still on 
a twig, singing merrily, while the others were keep- 
ing time with wings and feet in a kind of dance, 
and all twittering an accompaniment. He watched 
them for some time, and was satisfied that they 
were having a ball and concert, and thoroughly en- 
joying themselves ; they then became alarmed, and 
the performance abruptly terminated, the birds all 
going off in different directions. The natives told 
