THE REACTION OF CERIANTHUS TO TWO SOURCES OF LIGHT.

1. In case Cerianthus is acted upon by two lights of unequal intensities the relation between the angle turned and the ratio between the intensities of the two lights is mathematically expressed by the equation log(10) See PDF for Equation tan a, in which See PDF for Equation is the ratio of the two lights, a is the angle turned from the neutral position, and K = 0.615. 2. According to published data from experiments on other animals, the relation between the angle turned and the ratio between the intensities of the two lights may be expressed by the same equation.