THE PLAY OF ANIMALS. 225 



sometimes even takes part in his battles. A description 

 already quoted says: " Sometimes a female is found on 

 the arena taking up a position like that of the males 

 and running about with them; but she does not long 

 mingle in the strife, and soon runs away." No clearer 

 proof could be desired that the female feels a secret 

 sympathy in the love-plays carried on before her, for 

 in such a case it evidently clamours for expression 

 until the impulse to join in the song or dance is irresist- 

 ible, as in the orgies described by Middendorf. Many 

 birds arrange a regular stage or arena. Hudson says: 

 "There are human dances in which only one person 

 performs at a time, the rest of the company looking 

 on, and some birds in widely separated genera have 

 dances of this kind. A striking example is the rupicola, 

 or cock-of-the-rock, of tropical South America. A 

 mossy level spot of earth surrounded by bushes is se- 

 lected for a dancing place, and kept well cleared of 

 sticks and stones; round this area the birds assemble, 

 when a cockbird, with vivid orange-scarlet crest and 

 plumage, steps into it, and with spreading wings and 

 tail 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, becom- 

 ing exhausted, he retires, and another bird takes his 

 place." * 



There are examples on record, too, that seem to in- 

 dicate that some of the higher animals observe the 

 movements of others than their own kind with a sort 

 of aesthetic perception. The most familiar of these is 

 that of a dog looking out of a window. Schopenhauer 

 considered this critical watching of passersby that can 



* The Naturalist in La Plata, p. 261. 



