256 THE PLAY OF ANIMALS. 



ically developed very early and ready for pairing in 

 the first autumn of his life, but, with the exception of 

 the crossbill, this is not the case with the birds that have 

 been mentioned. The awakening of love seems to fill 

 these little creatures only with a beautiful tenderness, 

 which inspires them to express their joy in song and 

 other demonstrations.* Hudson tells us that many spe- 

 cies of American woodpeckers engage in a kind of duet 

 which is practised in their earliest youth. " On meet- 

 ing, the male and female, standing close together 

 and facing each other, utter their clear, ringing con- 

 cert, one emitting loud, single, measured notes, while 

 the notes of its fellow are rapid rhythmical triplets; 

 their voices have a joyous character, and seem to ac- 

 cord, thus producing a kind of harmony. This manner 

 of singing is perhaps most perfect in the oven bird 

 (Furnarius), and it is very curious that the young 

 birds, when only partly fledged, are constantly heard in 

 the nest or oven apparently practising these duets in the 

 intervals when the parents are absent; single, measured 

 notes, triplets, and long, concluding trills are all re- 

 peated with wonderful fidelity, although these notes 

 are in character utterly unlike the hunger cry, which 

 is like that of other fledglings." f 



It would seem, then, to be firmly established, among 

 birds at least, that the arts of courtship are practised 

 as youthful sport before the time for reproduction. In 

 choosing the examples cited from Brehm I have inten- 

 tionally included some that refer to flying and dancing 

 motions, as well as to singing. 



* Brehm, Beitrage znr Vogelkunde, ii, pp. 747-756, 

 \ Th* Naturalist in La Plata, p. 256. 



