A Light Polarization Analyzer in the Compound Eye of Limulus

Abstract

Single element receptor and nerve systems are isolated from the lateral eye of Limulus (Xiphosura polyphemus) by manual dissection, and the action potential discharges in the single elements are recorded when illuminated by light of constant intensity which is plane-polarized by passage through a Polaroid disc. When the Polaroid plate is rotated the frequency of the discharge in the nerve varies, going from maximum to minimum in a 90[degree] rotation. Two complete cycles appear during a 360[degree] rotation. In the 2 units reported on, the frequency varied 15% and 23%, respectively, between max. and min. Rotation of the eye unit with the polarizer stationary gives a similar effect.