In the slowly adapting stretch receptor neurons the temporal decline of the impulse frequency in response to intracellular current stimulation can be interpreted--apart from the high initial overshoot--by the sum of two exponential functions with time constants of approximately 1 and 10 s. In the rapidly adapting cells the discharge frequency decays--after only a little initial overshoot by current step stimulation--nearly rectilinear with about 8 imp./s2 and stops suddenly mostly in the range of 5 s. The current-frequency-characteristic curves show for both receptor cell types nearly straight lines to 7 nA.