T H E Loci of Action of Ultraviolet and X-radiation and of Photorecovery

This paper describes experiments on the effects of ultraviolet radiation and of x-rays on the eggs and sperm of the sea urchin Arbacia punclulata, carried out during the summer of 1950.1 These, together with earlier findings already described (Blum and Price, 1950 a, b; Blum, Loos, and Robinson, 1950) permit certain conclusions to be reached regarding the locus of action of these radia-' tions, and that of photorecovery after ultraviolet radiation. To aid in understanding the rationale of the experiments and their interpretation the results will be briefly recapitulated.