concerned. Such a view renders the study of the
larynx much more interesting and rational; one is then engaged in
working out that solution of a problem which Nature has accomplished.

The vocal cords, we can conceive, might be either relaxed or
tightened, and lengthened or shortened, or both, and beyond that we
can scarcely understand how they might have been modified so as to be
effective in the production of sounds of different pitch. As a matter
of fact, these are the methods Nature has employed to accomplish her
purpose. For each vocal cord one fixed point, and only one, is
required. We know of only one method in use by Nature to cause
movement in living structures--viz., contraction, and muscle is the
tissue which above all others has that property; hence the movements
of the vocal cords are brought about by muscles. But both for the
attachment of the muscles and the vocal cords themselves solid,
relatively hard structures are required. Bone would prove too
unyielding, but cartilage, or gristle, meets the case exactly. The
entire framework of the larynx--its skeleton, so to speak--is made up
of a series of cartilages united together so as to ensure sufficient
firmness with pliability.

The cartilages have been named from their shape, as that appealed to
the original observers, and the terms employed are of Greek origin.
The largest and strongest is the _thyroid_ (_thureos_, a shield)
cartilage, which resembles somewhat two shields put together in front
without any visible joint, and open behind but presenting a strongly
convex surface externally, in front and laterally. "Front" (anterior)
and "back" (posterior) always refer in anatomy to the subject
described, and not to the observer's position. In observing another's
larynx the subject observed and the observer naturally stand front to
front, and it is impossible to see or touch the back of the larynx as
it is covered behind by the other structures of the neck.

This thyroid, the largest of the cartilages, is attached to the hyoid
or tongue bone above by a membrane, so that the whole larynx hangs
suspended from this bone by a membrane, though not by it alone, for
muscles are attached to it which also serve for its support. It is of
practical importance to remember that the larynx is free to a very
considerable extent, otherwise it would go ill with the voice-producer
in the vigorous use of the voice, not to mention the advantages of
mobility as well as pliabi