GENESIS OF BIRD-SONG. 9? 



vocal performance is possible, because the 

 lower mouth space and the tongue are singu- 

 larly adapted to modifying and breaking up 

 the voice into fragments surprisingly articu- 

 late, though the voice itself is inferior in 

 timbre and range. 



Long before I began my dissections, I had 

 noted that the sweetest of the flute notes ut- 

 tered by the mocking-bird and the blue- jay 

 appeared to be blown out through a rigidly 

 distended throat, whilst the delicately qua- 

 vered passages of the mocking-bird's song 

 were, seemingly, manufactured at the root 

 of the tongue. To get evidence of this, care- 

 fully watch your caged mocker when he is 

 delivering a labored staccato combination, 

 and you will see the convulsive shake of the 

 mouth muscles and the peculiar management 

 of the lower mouth space, by which he differ- 

 entiates the notes. On the other hand, he 

 will whistle, and when he has ended you can 

 scarcely say whether or not he opened or 

 moved his mouth at all during the perform- 

 ance. 



There is an interesting ventriloquial effect 

 produced by the purely syringeal or laryn- 

 geal notes of a bird's voice. This is very 

 pronounced in the call of the quail, and es- 

 pecially in the piping of young wild turkeys ; 

 but it is most noteworthy in some of the 

 night-cries of the mocking-bird. True song, 

 however, has nothing of this peculiarity in it ; 

 even the careless shadow lay of the indigo- 

 bird has its definite expression of place and 

 distance, no matter how sketchy its outline. 



From all we can gather it appears most 

 probable that in its present form our song- 

 bird proper our bird with a song to sing is 

 not much older than man ; that he found his 



