Functional characteristics of stretch receptors of flight apparatus of cockroach Periplaneta americana.

The functional characteristics of the stretch receptors of the wing joints of Periplaneta americana were examined and the possible functional role of these receptors in the maintenance of a stable rhythm of flight is discussed. The stretch receptors of the wing joints are of the phasic-tonic type, with slow and incomplete adaptation by the receptors which discharge upon movement of the wing upward. The nature of the impulse response of a receptor depends both on the angle and the rate of movement of the wing membrane. The arrangement of a hypothetical pacemaker of the insect's wing beats is discussed in detail.