for the discharge of the nervous impulses
running in each case to the muscles which were moved. The evidence
recently forthcoming, however, is leading investigators to think that
there is no cortical centre for the "motor" or outgoing processes
properly so called, and that these Rolandic areas, although called
"motor," are really centres for the incoming reports of the movements
of the respective muscles after the movements take place, and also for
the preservation of the memories of movement which the mind must have
before a particular movement can be brought about (the mental images
of movement which we called on an earlier page Kinaesthetic
Equivalents). These centres being aroused in the thought of the
movement desired, which is the necessary mental preparation for the
movement, they in turn stimulate the real motor centres which lie
below the cortex at the second level. This is in the present writer's
judgment the preferable interpretation of the evidence which we now
have.

[Illustration: FIG. 5.--The speech zone (after Collins).]

_The Speech Zone._--Many interesting facts of the relation of body and
mind have come to light in connection with the speech functions.
Speech is complex, both on the psychological and also on the
physiological side, and easily deranged in ways that take on such
remarkable variety that they are a source of very fruitful indications
to the inquirer. It is now proved that speech is not a faculty, a
single definite capacity which a man either has or has not. It is
rather a complex thing resulting from the combined action of many
brain centres, and, on the mental side, of many so-called faculties,
or functions. In order to speak a man normally requires what is called
a "zone" in his brain, occupying a large portion of the outside
lateral region (see Fig. 5). It extends, as in the figure, from the
Rolandic region (_K_), where the kinaesthetic lip-and-tongue memories
of words are aroused, backward into the temporal region (_A_), where
the auditory memories of words spring up; then upward to the angular
gyrus in the rear or occipital region (_V_), where in turn the visual
pictures of the written or printed words rise to perform their part in
the performance; and with all this combination there is associated the
centre for the movements of the hand and arm employed in writing, an
area higher up in the Rolandic region (above _K_). In the same general
zone we also find the music function locat