Osservazioni preliminari sui potenziali elettrici delle libellule per stimoli luminosi

Summary

(1) In the dragon-fly's eye, the “on” rhythm, which is the index of the dark-adapted eye, is obtained with adaptation times of very short duration (up to 7/10 s).

(2) The after rhythms (dark rhythm), which are present after cessation of illumination, appear in the dragonfly's eye also after light adaptations of very short duration (0.8 σ exposure) and at a room temperature of 18° C. Therefore the threshold of optic stimulation in the dragon-fly is very low.

(3) With the diminution of time exposure duration (from 200 to 0.8 σ), the latent period increases and the duration of response decreases.