and to regulate the tension of the vocal cords, because the
vibrations of these are considered the determining factor of vocal
pitch. Sir Morell Mackenzie, however, in describing the muscles of the
larynx in a passage couched in untechnical language, unconsciously gives
a hint of another purpose for which the complexity of muscles in the
larynx may exist. After speaking of the "innumerable little fingers of
the muscles which move the vocal cords," he continues: "These fingers
(which prosaic anatomists call _fibres_), besides being almost countless
in number, are arranged in so intricate a manner that every one who
dissects them finds out something new, which, it is needless to say, is
forthwith given to the world as an important discovery. It is probable
that no amount of macerating or teasing ever will bring us to 'finality'
in this matter; nor do I think it would profit us much as regards our
knowledge of the physiology of the voice if the last fibrilla of tiny
muscle were run to earth. The mind can form no clearer notions of the
infinitely little than of the infinitely great, and the microscopic
movements of these tiny strips of contractile tissue would be no more
_real_ to us than the figures which express the rapidity of light and
the vast stretches of astronomical time and distance. Moreover, no two
persons have their laryngeal muscles arranged in precisely the same
manner--a circumstance which of itself goes a considerable way toward
explaining the almost infinite variety of human voices. The wonderful
diversity of expression in faces which structurally, as we may say,
are almost identical, is due to minute differences in the arrangement
of the little muscles which move the skin. The same thing holds good of
the larynx."

These are significant words. The distinguished physician who wrote them
might just as well have said that the generally prevailing theory that
in voice-production the muscles of the larynx exist solely to open and
close the glottis and to regulate the tension and hence the vibration of
the vocal cords, is incorrect. For they also exist in order to shape and
reshape the entire larynx within itself according to the note to be
produced, and the opening or closing of the glottis with the degree of
tension of the vocal cords resulting therefrom is but one detail in the
coordination of adjustments and readjustments which prepare the vocal
tract to produce the tone the singer hears in his mind. Nearly e