In considering the pathology of otosclerosis one finds in the literature a large number of reports1 and considerable differences of opinion as to the interpretation of the observations. Most of the discussions have centered about the changes in the bony capsule of the labyrinth. However, Gray2 has written several times about changes in the eighth nerve. He has expressed the belief that he has found a localized loss in the neurokeratin of the medullary sheaths and a similar absence in the neurilemma of the cochlear nerve. These changes were absent in the vestibular division. Other observers have found degeneration in the organ of Corti, the spiral ganglion and the eighth nerve.
In considering these changes one must remember the normal difference between the two divisions of the eighth nerve. The fibers of the vestibular branch are normally larger, more distinct and more easily seen. The neurokeratin