latest experiments in physiological and
anatomical science seem to favor the theory that it is in some way
connected with the harmony of the movements. This co-ordination, by
which the adjustment of voluntary motion is supposed to be effected, is
not in reality a _faculty_ having its seat in the brain substance, but
is the harmonious action of many forces through the cerebellum.

The _Cerebrum_ occupies five times the space of all the other portions
of the brain together. It is of an ovoid form, and becomes larger as it
approaches the posterior region of the skull. A longitudinal fissure
covered by the dura mater separates the cerebrum into two hemispheres,
which are connected at the base of the fissure, by a broad medullary
band, termed the _corpus callosum_. Each hemisphere is subdivided into
three lobes. The anterior gives form to the forehead, the middle rests
in the cavity at the base of the skull, and the posterior lobe is
supported by the tentorium, by which it is separated from the cerebellum
beneath. One of the most prominent characteristics of the cerebrum is
its many and varied _convolutions_ These do not correspond in all
brains, nor even on the opposite sides of the same brain, yet there are
certain features of similarity in all; accordingly, anatomists enumerate
four _orders of convolutions_. The first order begins at the _substantia
perforata_ and passes upward and around the corpus callosum toward the
posterior margin of that body, thence descends to the base of the brain,
and terminates near its origin. The second order originates from the
first, and subdivides into two convolutions, one of which composes the
exterior margin and superior part of the corresponding hemisphere, while
the other forms the circumference of the _fissure of Sylvius_. The third
order, from six to eight in number, is found in the interior portion of
the brain, and inosculates between the first and second orders. The
fourth is found on the outer surface of the hemisphere, in the space
between the sub-orders of the second clasp. A peculiar fact relating to
these convolutions is observed by all anatomists: mental development is
always accompanied by an increasing dissimilarity between their
proportional size.

The cerebral hemispheres may be injured or lacerated without any pain to
the patient. The effect seems to be one of stupefaction without
sensation or volition. A well-developed brain is a very good indication
of intelligence