OF THE TRUMPETER BIRD. 
5S1 
upper cartilage of the bronchial tubes. The bronchial 
tubes perforate the bangs in the usual manner; and the 
surface of the lungs exhibits to the eye numerous small 
perforations communicating with the great air-cells. 
The extraordinary structure of the lower larynx in the 
PsopJiia, cannot fail to have much influence on its voice. 
The excellent description which Cuvier has given of the 
mechanism of the organs of voice in birds^ and his very 
decisive experiments, leave it not doubtful that the lower 
larynx is the organ by which the sound is produced, al- 
though the modifications of its tone are influenced by the 
length and form of the trachea, and the contractions and 
dilatations of the upper larynx. The lower larynx may be 
considered, in relation to the organs of voice in birds, as 
the mouth -piece to the clarionet or flageolet,- — the part 
where the sounds are formed ; while the elongation of the 
trachea, or the contraction of the rima glottidis, merely 
vary the intensity of the intonation; just as lengthening a 
flute, by means of its sliding joint, deepens its tone; or as 
the hand of the player introduced into the expanded ex- 
tremity of a French horn, afi'ects the tension of the notes of 
that instrument. 
In the bird now under consideration, the division of the 
aerial current must weaken its force, and the vibrations of 
the membranes of the lower larynx will therefore be less 
quickly performed, and, consequently, the voice of the bird 
reduced to a lower key, than if the current of air had acted 
in an undivided stream. 
The ventriloquism of the Psophia appeared to me to be 
performed during inspiration; and it has been alleged, 
that persons who have acquired this curious faculty, utter 
their words during the act of receiving air into the lungs, 
whenever they wish to exhibit their art. The powerful 
L I 9> 
