270 



The Naturalist in La Plata. 



joufFed-out plumage and staiiding exactly abi-east, 

 stoop forward and downwaid until the tips of their 

 beaks touch the ground, and, sinking their rhyth- 

 mical voices to a murmur, remain for some time in 

 this posture. The performance is then over and 

 the visitor goes back to his own ground and mate, 

 to receive a visitor himself later on. 



Dance of S|)ur-winged Lapwings, 



In the Passerine ordor, not the least remarkable 

 displays are witnessed in birds that are not 

 accounted songsters, as they do not possess the 

 highly developed vocal organ confined to the sub- 

 order Osciues. The tyrant-birds, which represent 

 in South America the fly-catchers of the Old World, 

 all have displays of some kind; in a vast majority 

 of cases those are sini]ily joyous, excited duets 



