A view of the under surface of the brain, which rests on the floor of the skull, shows the origin of important nerves, called the cranial nerves, the cerebellum, the structure connecting the optic nerves (optic commissure), the bridge of nervous matter (pons Varolii) connecting the two hemispheres of the cerebellum, and lastly numerous and well-marked convolutions. 268.

Commissure (Lat. con, together, and mitto, missum, to put).

It is softened by alkalies, such as caustic potash or soda and ammonia, the parts first attacked being the commissures, then the frog, and afterwards the sole and wall.

At the same time the lines of the face become drawn, the commissures of the lips pulled upwards, the eyes staring and haggard, the eyelids puckered, the nostrils extended, and the whole expression indicative of the intense and agonizing pain of the disease.