222 On the Laryngoscope. | April, 
and expansions of the air, or the successive and regular explosions 
which it produces in passing through the glottis.” It may be 
inspiratory or expiratory; the latter, however, will be alone referred 
to in the followmg observations. The inferior or true vocal cords 
alone give origin to sounds, the superior or false cords taking no 
part in the generation of these sounds, whatever their register 
or intensity may be. When we desire to produce a sound, the 
arytenoid cartilages approach one another with an astonishing 
mobility and freedom of action. The vocal cords, thus becoming 
approximated, assume what is termed “the vocalizing position.” 
In the production of the lower notes, the vocal cords are seen to 
vibrate throughout their entire length, and, probably, throughout 
their entire breadth also. As the voice ascends from’ its lowest to 
its more acute notes, the lengths of the vibrating portions of the 
vocal cords are proportionally diminished, their tensions are in- 
creased, and the arytenoid cartilages become more closely apposed. 
The vocal cords, in fact, present the same phenomena as those 
of musical cords, and appear to obey the same laws.* It is almost 
impossible to study the condition of the larynx during the pro- 
duction of the lowest chest sounds, because the arytenoid cartilages, 
becoming elevated, rapidly approach one another, even to complete 
zontact, and bend themselves undcr the border of the depressed 
epiglottis, so that this latter entirely conceals from vision the 
interior of the larynx,—vide Fig. 4. There is, in all probability, 
however, no considerable difference in the behaviour of the larynx 
during the emission of the gravest sounds and those less grave. 
The appearance of the glottis when Do' of the chest register is 
sounded has been represented in Fig. 5. The state of the interior 
of the larynx during the emission of the most acute sounds is, on 
the other hand, very readily observed. The glottis is contracted 
into a linear form, and the various parts of the larynx are felt to 
be in a state of great tension,—-vde Fig. 6. Three registers 
of the expiratory voice are generally described: the chest register, 
which commences lower in a man’s yoice than ma woman’s; the 
falsetto register, extending equally in both voices; and the head 
register, which reaches higher im the female voice. 
Se “>. Falsetto. 
Table of the Human Voice in its full Extent. 
Garcia has observed, that during the production of the chest 
* Vide ‘Observations on the Movements of the Larynx when viewed by means 
of the Laryngoscope, by J. Bishop, F.R.S., in ‘ Proceedings of the Royal Society 
London, June 5, 1862. Vol. xii. 
