scale, and that its action must necessarily cease, to a great
extent, when a certain point in the pitch is reached, as there is a
limit to the degree of contraction of all muscles; and, besides, the
crico-thyroid space is of very moderate size, and the cricoid
cartilage can ascend only within the limits thus determined. It thus
follows that Nature has provided in the change of mechanism for a new
register, which is nothing else than a change of mechanism with a
corresponding change of function. It will be at once apparent that the
claim that registers are an invention of men, and without foundation
in nature, is without support in anatomy and physiology. The
crico-thyroid is probably, however, of much more importance to tragic
actors and barytones than to tenors or sopranos. This, however, is no
excuse for the neglect of its development by the latter class, as
often happens, for without it the best tones of the lower register are
impossible. On the other hand, the elocutionists who prescribe for
students practices that involve the excessive use of this muscle, with
a cramped position of the vocal organs, the larynx being greatly drawn
down, with the view of producing disproportionately heavy lower tones,
must take no comfort from the above anatomical and physiological
facts. Art implies proportion, and it was one of the ambitions of all
the best actors in the golden age of histrionic art to have an "even
voice"--_i.e._, one equally good through the whole range required. The
tragic actor, elocutionist, and public speaker, and the singer,
whether soprano or bass, should neglect no muscle, though they may be
justified in developing some in excess of others, but ever with a
watchful eye on the weakest part.

2. The muscles which regulate the tension of the vocal bands are the
following:

(_a_) The _thyro-arytenoid[=e]us_ (pair), which by tilting the
arytenoid cartilages forward relaxes the tension of the vocal bands.
When they act with the adductors--_e.g._, the arytenoid[=e]us
proprius--the result must be relaxation and approximation behind,
which implies a greater or less degree of shortening, as usually
happens when a certain point in an ascending scale is reached in
persons whose methods of voice-production have not been in some way
modified, and a new register begins, which in most female voices is
marked by a more or less distinct and abrupt alteration of the quality
of the tone.

The crico-thyroids are the antag