Page:Popular Science Monthly Volume 25.djvu/635

 If, now, we take models of four brains, and on the first mark out the location of the various areas connected with the various sensory-organs as determined by the anatomical connection of the white nerve-threads; on the second mark out the location of the various areas which physiologists have shown to govern various sensory organs; on the third mark out the various areas whose disease produces disturbance of action in the various sensory organs, and loss of memories of perceptions by those organs; and on the fourth mark out the various areas which wither after disease of the various sensory organs—we shall find that upon all four brains the areas belonging to any one organ coincide. We may therefore conclude that each class of sensations



and each class of memories has its own definite area of the gray matter on the surface of the brain. Memories of objects seen are located in the posterior part in the occipital region. Memories of sounds heard are located in the lower lateral part in the temporal region. Memories of motions in the limbs, and of touch in those limbs, are located side by side in the central lateral region. Memories of speech