THE PLAY OF ANIMALS. 213 



claws, give a kind of exhibition which apparently serves 

 the purpose of displaying their wing decorations, which 

 are concealed, under ordinary circumstances. From 

 twelve to fifteen of them come together at the signal, 

 form in a close mass, and, while producing short, quick- 

 ly repeated notes, unfurl their wings like a standard of 

 banners. Some hold them upright and rigid, others 

 keep them half open with quick vibration, and still 

 others wave them with slow, regular motion back and 

 forth.* 



In all these examples, which might easily be mul- 

 tiplied, courtship is evidently the unconscious basis, as 

 any unbiased mind must be convinced by a glance at 

 the following chapter. When the contagious influence 

 of imitation becomes a factor in mass games, they are 

 easily converted into veritable orgies. I think we en- 

 counter here among the birds the same principles that 

 govern ethnology and the history of human civilization. 

 Their plays correspond with our general dance that is 

 so closely connected with sexual excitement, and the 

 examples given above may be likened to Middendorf s 

 description of a dance of savages. " The dance soon 

 became boisterous, the movements mere leaps and hops, 

 the faces inflamed, the cries more and more ecstatic 

 as each tried to exceed the others. The fur coats and 

 breeches were thrown off, and they all seemed to be 

 seized with a frenzy. Some, indeed, made an effort 

 to withstand it, but soon their heads took the motion, 

 now right, now left, till suddenly the onlookers leaped 

 among the dancers as if they had broken some con- 

 trolling bonds, and widened the circle." f 



* See The Naturalist in La Plata, p. 265. 

 t 0. Stoll, Suggestion und Hypnotismus in der Volkerpsycho- 

 logie, Leipzig, 1894, p. 24. 



