, in the peripheral field of vision. The
occipital movement would, therefore, be excited through the retina, and
would result in bringing the yellow spot region of the retinae of both
eyes to bear upon the object. This view has much to justify it. The
movements of the eyeballs excited from the cortex of the auditory region
would in a similar way be explicable as bringing the gaze to bear upon a
direction in which a sound had been located, auditory initiation
replacing the visual and tactual of the occipital and the frontal
regions respectively.

Turning from these still speculative matters to others less suggestive
but of actual ascertainment, we find that the motor nature of the
precentral cortex as ascertained by electric stimuli is further
certified by the occurrence of disturbance and impairment of motor power
and adjustment following destruction of that region of the cortex. The
movements which such a part as a limb executes are of course manifold in
purpose. The hind limb of a dog is used for standing, for stepping, for
scratching, for squatting, and, where a dog, for instance, has been
trained to stand or walk on its hind legs alone, for skilled acts
requiring a special training for their acquisition. It is found that
when the motor area of the brain has been destroyed, the limb is at
first paralysed for all these movements, but after a time the limb
recovers the ability to execute some of them, though not all. The
scratching movement suffers little, and rapid improvement after cerebral
injury soon effaces the impairment, at first somewhat pronounced, in the
use of the limb for walking, running, &c., and ordinary movements of
progression. Even when both hemispheres have been destroyed the dog can
still stand and walk and run. Destruction of the motor region of the
cortex renders the fore limbs of the dog unable to execute such skilled
movements as the steadying of a bone for gnawing or the trained act of
offering the paw in answer to the command of the master. Skilled acts of
the limb, apart from conjoined movements in which it, together with all
the other limbs, takes part, assume of course a larger share of the
office of the limb in the Primates than in the dog; and this is
especially true for the fore limb. It is when the fore-foot becomes a
hand that opportunity is given for its more skilled individual use and
for its training in movements as a tool, or for the handling of tools
and weapons. It is these movem