258 THE PLAY OF ANIMALS. 



with an invisible leader. They followed one another 

 in pairs, forming circles in the shaded wood as if they 

 were in an arena. Other groups of three or four stood 

 by as spectators, or from time to time joined the circle. 

 This went on until my dog disturbed and scattered the 

 assemblage, but I had plenty of time to observe what 

 I have attempted to describe. I believe that it was the 

 breeding time of the animals, and for that reason they 

 were oblivious of the approach of danger." Brehm 

 says of the water rat: " Both sexes indulge in long- 

 continued gambolling before they pair. The male be- 

 haves very strangely. He turns so rapidly as to make a 

 whirlpool in the water. His mate looks on with appar- 

 ent indifference, but must secretly enjoy his exhibition, 

 for usually when it is finished she receives him with 

 favour." The whale in love " turns over on his back, 

 stands on his head, lashing the waves with his tail, 

 leaps up with his giant bride sportively above the water 

 and performs other antics." 



Observations on birds are exceedingly copious in 

 this connection. Two kinds of motion can be distin- 

 guished among them, which though sometimes found in 

 combination are quite unlike. I mean flying evolutions 

 and dancing motions. Taking flight first, we have 

 Brehm^s description of the blue-throated warbler: " In 

 sunny weather it tumbles about in the air and performs 

 the strangest evolutions, plunging headlong downward 

 it often turns a complete somersault, as Naumann * 

 says. Then mounting slowly upward once more he 

 flies like a dove, with quick movements of the wings 

 and apparently with no object in view." Azara, de- 

 scribing a small finch which he aptly named Oscilador, 



* Naturgeschichte der Vogel Deutschlands, ii, p. 164. 



