}82 LARYNX OF THE LOWER ANIMALS. 



Such is the structure of the organ of voice ; yet, simple 

 as it is, the mechanism of this function, is far from be- 

 ing established. It is agreed on all hands, that the voice 

 is formed at the moment when the air traverses the lar- 

 ynx, but physiologists are not agreed as to the part which 

 these ligaments act. Some have supposed that while 

 vibrating, they produce sounds like the strings of a vio- 

 lin, and have given them the name of Vocal Chords. 

 Others have compared them to the reed of a clarionet ; 

 while some have supposed that the sound is produced, 

 not by the vibrations of these ligaments, but merely by 

 the rushing of the air through the narrow opening of the 

 glottis ; by these, the larynx has been compared to a 

 flute, or whistle. 



Emily. The truth is, I suppose, that the subject is a 

 very obscure one, and every one who speculates upon 

 it, likes his own theory better than his predecessors'. 

 But let us see what they amount to. 



Dr. B. We cannot enter into a discussion of their 

 merits, for it would lead us too far into the science of 

 sounds. It may be remarked, merely, that it is certain, 

 that these ligaments the vocal chords do vibrate 

 when the voice is produced, and that they either pro- 

 duce, or essentially affect the sound. But the organ of 

 voice cannot be called a flute, a violin, nor a clarionet ; 

 it is a larynx, an instrument which art has as yet but im- 

 perfectly imitated. 



Forming now, in your mind, a distinct idea of the 

 human larynx, you will readily understand the points of 

 resemblance and difference between it and those of the 

 inferior animals. Among the mammiferous animals, 

 there is not one whose larynx is not provided with the 

 same apparatus as man's ; while in many we find parts 

 which he has not. So that with more complicated or- 

 gans, most of these animals produce only inarticulate and 

 disagreeable sounds. 



Emily. If then their larynx is formed like man's, 

 how are we to account for their inability to produce ar- 



