In 1934, while contemplating the regularity with which nystagmus is produced by stimulation of the vestibular branch of the eighth nerve, I theorized that when one part of the auditory nerve is so closely associated with the nerve of the eye it is reasonable to expect that the other part may have some similar association. This theory was easily and quickly put to the test. In 10 persons with normal hearing a sudden noise was seen to produce a movement of the pupils of the eyes. Careful analysis of this movement showed that it consisted of a distinct, rapid and consensual dilatation of the pupil. The dilatation was momentary and was quickly followed by contraction, even during the continuance of the noise.
A search of the literature revealed that a number of otologists had anticipated me with both the theory and attempts to prove it. Cemach1 in 1919 wrote an