dy described, conditions
are established in the cerebellum, such that given stimuli may act
_reflexively_ through it and produce definite results in the way of
muscular contraction. After the establishment of these conditions,
afferent impulses from the eyes, ears, skin, and other places, under the
general direction of the cerebrum, may cause such actions as the balancing
of the body, walking, etc., as well as the delicate and varied movements
of the hand. This view of its functions makes of the cerebellum the great
center of secondary reflex action.

*Functions of the Cerebrum.*--While the work of the cerebrum is closely
related to that of the general nervous system, it, more than any other
part, exercises functions peculiar to itself. The cerebrum is the part of
the nervous system upon which our varied experiences leave their
impressions and through which these impressions are made to influence the
movements of the body. But the power to alter, postpone, or entirely
inhibit, nervous movements is but a part of the general work ascribed to
the cerebrum as _the organ of the mind_. Numerous experiments performed
upon the lower animals, together with observations on man, show the
cerebrum to be the seat of the mental activities, and to make possible, in
some way, the processes of consciousness, memory, volition, imagination,
emotion, thought, and sensation.

*Localization of Cerebral Functions.*--Many experiments have been performed
with a view to determining whether the entire cerebrum is concerned in
each of its several activities or whether special functions belong to its
different parts. These experiments have been made upon the lower animals
and the results thus obtained compared with observations made upon injured
and imperfectly developed brains in man. The results have led to the
conclusion that certain forms of the work of the cerebrum are _localized_
and that some of its parts are concerned in processes different from those
of others.

[Fig. 142]

Fig. 142--*Location of cerebral functions.* Diagram of cerebrum, showing
most of the areas whose functions are known.

The work of locating the functions of different parts of the cerebrum
forms one of the most interesting chapters in the history of brain
physiology. The portions having to do with sight, voluntary motion,
speech, and hearing have been rather accurately determined, while
considerable evidence as to