ENOIDEUS).

4, 5. RING-PYRAMID MUSCLE (CRICO-ARYTENOIDEUS).

6. SHIELD.

7. LEFT UPPER HORN.

8. PYRAMID.

9. RING.

10. WINDPIPE.
]

It may be observed here that it is impossible to imitate, in the
dead subject, the contraction of the vocal muscles. All
conclusions, therefore, drawn from experiments upon exsected
larynges, with regard to tone-production in living man are
necessarily quite untrustworthy, and cannot for one moment be
admitted as evidence against observations made upon singers with
the laryngoscope.

These two pairs of muscles, then, namely the ring-shield muscles (pl.
VIII, 1, 2) and the shield-pyramid muscles (pl. IX, 1, 2, 3) by
stretching, slackening, and compressing the vocal ligaments, mainly
govern the pitch of the tones produced by their vibrations. The
ring-shield muscles receive some assistance in stretching the vocal
ligaments from another quarter, of which we shall speak later on.

We have now had a look at the vocal ligaments, and we have seen by what
means they are put on the stretch. As, however, in a state of repose
these ligaments diverge behind, they must be brought parallel to each
other before they are ready for the production of sound. Let us,
therefore, in order to explain how this is done, imagine that we have
cut off that part of the pyramids which is standing out above the vocal
ligaments (pl. VII), and let us now have a look at these parts from
above. You see the ligaments (pl. XA, 1, 2), a section of the pyramids
(pl. XA, 3, 4), and uniting these an elastic band (pl. XA, 5). The space
between these parts is commonly called the Glottis, but as this
appellation belongs more properly to the vocal ligaments, it is
manifestly wrong to give the same name to the _space_ which they
inclose. This space should be distinguished as the "_Chink_ of the
Glottis" or the "Vocal Chink."

I have been blamed for making this distinction in the face of
almost universal usage. But I can point to the great anatomist
Professor Luschka as having set the example, and while it is true
that in most physiological works "Glottis" is used for the _slit_
between the vocal ligaments, yet the appellations "Rima glottidis"
and "Aperture of the glottis" are also employed for the same thing.
Medical men, moreover, speak of "Spasm of the glottis," and singing
masters of the "Shock of the glottis," which terms are clearly