The effects of stimulation of the labyrinth of the ear in the living animal. (With demonstration.)

It may be shown that if one sits in a moving railway train and observes objects out of the window, they may seem to be moving in a direction opposite to that of the train. If one notices the movements of one's eyes in observing these objects, it will be seen that the eyes move slowly backward, opposite to the direction in which the train is going, and more quickly return to the median position, the quick movement of the eye being in the same direction as the movement of the train. We may express this relation between eye-movements and apparent movement of external objects or real passive movement of the one's own body by the statement that the apparent movement of external objects is in the direction of the slow deviation of the eyes, and the real passive movement of one's body is in the direction of the quick movement of the eyes. The otic labyrinth is not involved in these reactions. We may extend this relationship still further and say that under whatever conditions of this kind, with one possible exception, 1 one may be placed the movement, either real or apparent, of external objects is in the direction of the slow deviation of the eyes, and passive movement, either real or apparent, of one's own body is in the direction of the quick movement of the eyes. While many of the facts have long been known, we have not seen any general expression of the relationships in terms of the slow and quick eye movements.

Stimulation of the otic labyrinth in a number of different ways, including rotation about a particular axis of the head, evokes movements of the eyes, and sensations of apparent movement of external objects or of one's own body, or both.