Are Birds Singers or Whistlers? 177 



whistle, such as the meadowlark sends across the green 

 fields. But suppose he desires to " blow a dreamy hautbois 

 note, slender and refined as ever stirred the air of Arcady 

 or trembled in the vineyards of old Provence," then all 

 the musician in plumes needs to do is to contract the slit 

 in his throat, depress his tongue, almost ciose his mandi- 

 bles, and simply allow a slender air current to sift from the 

 lungs through the syrinx and out of the glottis. What if 

 the whim should seize him to pipe a trill or a quaver to the 

 water witches of the meadow, as Master Song Sparrow so 

 often chooses to do? Then he simply needs to set his 

 tongue and throat to quivering, and you have his enrap- 

 ttiring tremolo. Beautiful, is it not? 



There are birds that send a kind of guttural sound from 

 their throats, such as the cuckoos and occasionally the 

 blue jays. Notice the cuckoo as he utters his call, which 

 every swain interprets as the harbinger of a coming 

 shower, and you will observe that his throat bulges out 

 like that of a croaking frog, and quivers at the same time 

 in a convulsed way. It is plain that the air about to be 

 forced from the glottis is flung back by some muscular 

 action and set to vibrating in the laryngean cavity, thus 

 giving the sound its croaking quality when the elastic 

 current is finally released. 



Now, if the reader will pucker up his lips and whistle 

 a tune, he will notice that the sound is actually produced 

 at the small labial orifice and nowhere else; however, the 

 tones are modified and modulated at will in a variety of 

 ways by a deft, though almost imperceptible, manipu- 



