COURTSHIP AND SEX 193 



prodigal, showering down as thick and fast as drops of rain 

 in a summer shower." Thus Brehm writes : " Dominated 

 by love, the jay sings, whistles, and murmurs, the magpie 

 chatters, the croaking raven transforms its rough sounds 

 into gentle, soft notes, the usually silent grebe lets its voice 

 be heard, the diver sings its wild yet tuneful ocean-song, 

 the bittern dips its bill under water that the only cry at its 

 command may become a deep, far-sounding booming." 



What is the unity in all this diversity ? It is that each 

 bird is primarily saying, according to its mood and skill : 

 " Hither, my love, here ; here I am, here ! " But the song 

 of birds will be woefully misunderstood if we simply write 

 it down as an elaborate sex-signalling. It is that primarily, 

 just as serenading is, but it is much more. In true songsters 

 at the pairing season the song is indicative of passion ; 

 it is a soliciting of the female's attention, interest, and 

 acquiescence. But it has come to be an expression of emo- 

 tions that have gathered round the passion of fondness, and 

 it may manifest itself away from any immediacy of sex-desire. 

 We have a peculiar right to insist on this in the case of birds 

 because sex-activity is in most cases very sharply punctuated 

 among them ; there is a waning of the reproductive organs 

 after the breeding season is over. But it is well known that 

 many birds have a second singing after the tide of sex has 

 ebbed for the year. It would be unwarrantable to say that 

 song may pass entirely beyond the confines of sex, for that 

 would mean a denial of the unity of the organism. But the 

 facts indicate that it may pass far beyond being an 

 expression of sex- desire. 



§ 8. The Vocal Organs 



Whereas in mammals the vocal cords are in the larynx, 

 at the top of the windpipe, in birds they are situated in a 

 special song-box, the syrinx, at the foot of the windpipe, 

 where it branches into the two bronchial tubes leading to the 

 lungs. Birds have a larynx, but it is voiceless — one of the 



O 



