Everything on earth is in motion with reference to any fixed point in space. Motion, therefore, is a primary force in life; indeed, absence of motion is death. Man moves and is affected by motion.
The master mechanism controlling our motion is a modest little special sense organ housed in the walls of the labyrinth deep within the protective ramparts of the temporal bone in the middle of the skull. The fact that the labyrinth is the only organ in the body which has reached its full size and development at the time of birth is significant. The skull of early man shows the labyrinth has not been modified by nature during the thousands of years of man's effort to conquer the physical world. Man alone has the power of speech. Full exploitation of speech is dependent upon hearing. Again it is significant that the labyrinth is the seat of