Longitudinal Fissure

The great fissure separates the cerebrum into two hemisphere and reaches from the front to the back of the organ; it contains a vertical process of the dura mater, the falx cerebri. In front and behind it extends from the top to the bottom of the cerebrum, and completely separation to two hemispheres, but its middle portion only separates the hemispheres for about half their vertical extent, the floor of this part of the fisure being formed by the great central white commissure, the corpus eallosum, which connects the two hemisphere together.

The remaining fissure are situated inn one or other of the two hemispheres, with the exception of the transverse fissure, one half of which is contained in each hemisphere.

Sylvian Fissure
This fissure is a well marked cleft on the base and side of the hemisphere. Starting at the base of the brain in a depression, the valleecula sylvii, in which is situated the anterior perforated space, it passes outward to the external surface of the hemisphere. It here gives off a short anterior limb, which passes forward, and a short ascending limb, which passes upward into the interior frontal convalution. It is then continued backward as the horisontal limb, which terminates by an upward inflexion in the parietal lobe. It occupies the middle third of the lateral surface of the hemisphere.