E.

1, 2. SECTION OF THE PYRAMIDS WITH VOCAL LIGAMENTS AND ELASTIC BAND.

3, 6, 3. RING.

7. PYRAMID MUSCLE (ARYTENOIDEUS TRANSVERSUS).

8, 9, 10. SHIELD.

11. BANDS BY MEANS OF WHICH THE PYRAMIDS ARE ATTACHED TO THE RING.

4 & 5. BACK RING-PYRAMID MUSCLES (POSTERIOR CRICO-ARYTENOIDEI).

1, 3 & 2, 3. SIDE RING-PYRAMID MUSCLES (LATERAL CRICO-ARYTENOIDEI).

NOTE.--The shield-pyramid muscles (Thyro-Arytenoidei) which run parallel
with the vocal ligaments are, for the sake of clearness, omitted from
this diagram.]

These "Side Ring-Pyramid Muscles" (pl. XI, 3, 1 and 3, 2; see also pl.
IX, 5, 4) are assisted by a single muscle uniting the pyramids behind
the elastic band which we have already noticed. This muscle we will call
the "Pyramid Muscle" (pl. XI, 7). By the united action of the muscles
which have just been described the vocal chink is thrown in the shape
shown on pl. X, C, and the vocal ligaments are now in a proper position
for the production of tone.

* * * * *

Before proceeding any farther it will be well if we once more glance at
the muscles with which we have become acquainted, so that we may be
quite sure about their functions.

MUSCLES:

I. GOVERNING THE SHAPE OF THE VOCAL CHINK.

The Back Ring-Pyramid} OPENING
Muscles } THE VOCAL CHINK.

THESE ARE OPPOSED BY--

The Side Ring-Pyramid }
Muscles, and the Pyramid} CLOSING
Muscles, assisted by the} THE VOCAL CHINK.
Shield-Pyramid Muscles }

II. GOVERNING THE PITCH OF THE TONES.

The Ring-Shield Muscles, } STRETCHING
assisted by the Back Ring-Pyramid }
Muscles } THE VOCAL LIGAMENTS.

THESE ARE OPPOSED BY--

The Shield-Pyramid } SLACKENING
Muscles } THE VOCAL LIGAMENTS.

=The Pocket Ligaments= (called "False Vocal Cords," pl. XII, 1 and 2) are
a pair of horizontal projections running above and parallel with the
vocal ligaments (pl. XII, 3 and 4). The pocket ligaments are, like the
vocal ligaments, attached in front to the shield and behind to the
pyramids. They may be described as two ledge-shaped pads mainly formed
of glands. They are very sensitive and movable, and ready on the
smallest incitement to meet with great rapidity in order to protect the
vocal ligaments from any harm. They must, therefore, be chiefly regarded
as safeguards of the vocal apparatus, though it is prob