the
general direction taken by the impulses in producing the action. The
impulses are, first, from the surface of the body to the central nervous
system; second, through the central system; and third, from the central
nervous system to the active tissues of the body.

Their chief differences are to be found, first, in the pathways followed
by the impulses, which are through the cerebrum (the organ of the mind) in
voluntary action, but in reflex action are only through the spinal cord or
the lower parts of the brain; and second, in the fact that voluntary
action is under the direction of the mind, while reflex action is not. It
would seem, therefore, that the statement sometimes made that "voluntary
action is reflex action plus the mind" is not far from correct. Mind,
however, is the important factor in this kind of action.

*Secondary Reflex Action.*--Everyday experience teaches that any voluntary
action becomes easier by repetition. A given act performed a number of
times under conscious direction establishes a condition in the nervous
system that enables it to occur without that direction and very much as
reflex actions occur. Actions of this kind are known as secondary reflex
actions, or as _acquired reflexes_. Walking, writing, and numerous other
movements pertaining to the occupation which one follows are examples of
such reflexes. These activities are at first entirely voluntary, but by
repetition they gradually become reflex, requiring only the stimulus to
start them.

The advantages to the body of its acquired reflexes are quite apparent.
The mind does not have to attend to the selection and direction of stimuli
and, to that extent, is left free for other work. A good example of this
is found in writing, where the mind apparently gives no heed to the
movements of the hand and is only concerned in what is being written. The
student will easily supply other illustrations of the advantages of
secondary reflex action.

The development of secondary reflexes probably consists in the
establishment of fixed pathways for impulses through the nervous system.
Through the branching of the nerve fibers many pathways are open to the
impulses. But in repeating the same kind of action the impulses are guided
into particular paths, or channels. In time these paths become so well
established that the impulses flow along them without conscious direction
and it is then simply necessary that some stimulus starts the impulses. By