The report describes the results of a system transfer function type study of the oculovestibular response to sinusoidal yaw angular oscillations of the head. Ten naval aviator candidates were exposed to Earth-vertical rotation about the z head axis at nine different, octave-separated stimulus frequencies covering the 0.005 to 1.28 Hz spectrum with peak velocity of the stimulus held constant at 50 deg/sec. The frequency dependence of the oculovestibular system was interpreted in terms of phase and amplitude measures of the slow component eye velocity element of the resulting horizontal nystagmus. Though the phase data collected at the lower stimulus frequencies deviated somewhat from those predicted by the conventional second-order model of cupula-endolymph response, a theoretical account for the deviation was postulated by introducing an adaptation transfer function as developed by other investigators.