ents which suffer most heavily and for the
longest period after injury of the motor region of the cortex. Hence the
disablement ensuing upon injury to the cortex would be expected to be
most apparent in the Primates; and it is so, and most of all in Man.
Further, in Man there ensues a condition called "contracture," which is
not so apparent or frequent a result in other animals,--indeed, does not
occur at all in other animals except the monkey. In contracture the
muscles of the paretic limb are not flaccid, as they are usually in
paralysis, but they are tense and the limb is more or less rigidly fixed
by them in a certain position, usually one of flexion at elbow and
wrist. This condition does not occur at first, but gradually supervenes
in the course of a number of weeks. In Man the destruction of the motor
area of the cortex cripples the limb even for the part it should play in
the combined limb movements of walking, &c., and cripples it to an
extent markedly contrasting with the slight disturbances seen in the
lower mammals, e.g. the dog.

As regards the recovery of motor power after lesions of the motor
cortex, two processes seem at work which are termed respectively
_restitution_ and _compensation_. By the former is understood the
recovery obtained when a part of a "centre" is destroyed, and the rest
of the centre, although thrown out of function at first, recovers and
supplements the deficiency later. An example of restitution would be the
recovery from temporary hemianopia caused by a small injury in one
occipital lobe. By compensation is understood the improvement of an
impaired nervous function, traceable to other centres different from
those destroyed supplying means to compass the reaction originally
dependent on the centres subsequently destroyed. Instances of such
compensation are the recovery of taxis for equilibrium subsequent to
destruction of the labyrinth of the ear, where the recovery is traceable
to assistance obtained through the eye. It will be noted that these
instances of recovery by restitution and by compensation respectively
are taken, from cases of injury inflicted on receptive rather than on
motor centres. It is doubtful how far they really apply to the undoubted
improvement that does within certain limits progress and succeed in
partially effacing the paresis immediately consequent on lesions of the
motor area. It has to be remembered that in all cases of traumatic
injury to the nervous sys