INTRODUCTION AND HISTORICAL REVIEW In 1908 B. Aschner1first observed that pressure on the eyeball caused slowing of the pulse and decrease in the depth of respirations. He found that it would arouse stuporous, anesthetized and unconscious patients, and enable them to respond to questions. He also showed that in narcosis the oculocardiac reflex lasts longer than the corneal or pupillary reflexes. Grossmann and Miloslavich2in 1912 made similar observations, and Fabre and Petzetakis,3working six years later than Aschner, confirmed the observation that the oculocardiac reflex persists even under deep ether or chloroform anesthesia, and can be elicited after the corneal reflex has gone. It was demonstrated by Aschner that the afferent impulse of the reflex passes through the trigeminal nerve to its nucleus in the midbrain, and that the efferent passes by way of the pneumogastric nerve. By cutting the third, fourth, sixth, seventh or