y, vowel sound, and power. Second, the
vocal organs prepare to adjust themselves, by the appropriate muscular
contractions, for the production of the tone mentally conceived. Third,
the fiat of will is issued, causing the muscular contractions to be
performed. These three operations are executed as one conscious,
voluntary act. Let us inquire to what extent consciousness is concerned
with each operation.

As conscious volitional impulses, the mental conception of the tone, and
the fiat of will to produce the tone, are well enough understood. These
two operations call for no extended consideration. We are at present
concerned only with the psychological laws bearing on the muscular
adjustments of the vocal organs.

Muscular contractions result from the transmission to the muscular
fibers of motor nerve impulses. These nerve impulses originate in the
motor nerve centers. They can never, under any circumstances, rise into
consciousness. Contractions of the voluntary muscles occur either as
reflex or as voluntary actions. In both cases the motor nerve impulses
originate in the same nerve centers. In the case of reflex actions these
lower muscular centers alone are involved; in voluntary actions the
originating of the motor impulses is "controlled" by consciousness. In
deciding that an action shall be performed, and in what way it is to be
performed, consciousness directs that each motor center involved shall
send out the appropriate discharges of nerve impulse.

Complex muscular activities require the sending out of nerve impulses
from various motor centers. Such activities are usually not performed
instantaneously, but require a longer or shorter time. Thus we may
consider it as one action for the writer to rise from his chair, to
lower the window and adjust the shade, and then to return to his seat.
In this case a large number of motor centers are successively involved;
at the proper instant each center discharges its impulse. To this end
the motor centers must be instructed when to come into activity.

This distribution of nerve impulse is effected by the power of
coordination. In voluntary actions coordination is accompanied by
conscious control.[9] But coordination is not a function of the higher
cerebral centers, that is, of consciousness. How the connection is made
between the higher cerebral centers and the lower motor centers is a
complete mystery. All that can be said is that the ideas of movements
are transmi