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. Bigg- Wither' s Pioneering in 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 ; 

 and on this spot, some on the stone and some on 

 the shrubs, were assembled a number of little birds, 

 about the size of torn-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 



