the heart-beat, the activity of the muscle probably
is determined largely by local stimulation. In the
case of breathing, the movements are wholly ini-
tiated by nerve-currents from centres in the cere-
bellum. The movements of swallowing are prob-
ably brought about through tactual sensations
(from the mouth) which excite certain nerve-centres,
which in turn excite the muscles of the mouth and
gullet. This last process is usually in part a con-
sciousness-reflex.

Actions of the second class are those in which
consciousness plays an important rôle, and of these
four types may be distinguished: sensational re-
flexes, or sensory-motor processes; perceptual re-
flexes; ideational reflexes, or ideo-motor processes;
and voluntary actions, or volitional processes.

In the sensational reflex the consciousness nec-
essarily involved is a sensation merely. Thus, the
hand is mechanically retracted upon coming into
contact with a hot object; the mere apprehension
of heat is sufficient to bring about the reaction, and
the apprehension of a definite hot object is not nec-
essary, although it may be important for further
action. Winking when a cinder gets in the eye, is
another typical sensational reflex. It is possible
that some of the instinctive actions of the young

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