Apparent Reversible Influence of Cosmic-Ray-Induced Showers upon a Biological System.

Abstract

Degree of disperson of the pigment of the melanophores of the fiddler crab, Uca. was studied in animals kept under lead plates. This was compared statistically with the degree of dispersion of similar random samples not kept under lead. Both in animals under lead plates and controls there were clear daily cycles of melanin dispersion. Animals under lead, however, showed pigment more dispersed than controls for 19 or 20 hours of the day. Only during the hours between 1 and 4 a.m. was the pigment of the animals under lead less dispersed than under the controls. It was concluded that increased cosmic-ray showers produced a statistically significant effect upon the melanin responses in the crabs and that there was a diurnal rhythm in the sign of the response to the increased showers.