THE EFFECTS OF ULTRA-VIOLET RADIATION OF λ2537A UPON CLEAVAGE OF SEA URCHIN EGGS

Abstract

Eggs of Strongylocentrotus purpuratus, irradiated with radiation of 2537A, showed a retarded cleavage when the dosage was sufficient. Below this dosage no evidences of acceleration of the cleavage rate were found for the dosages tried. Unfertilized eggs, eggs 15 and 90 min. after insemination and eggs in the 1st cleavage were not markedly different in susceptibility to the dosages tried, the later stages being somewhat more susceptible. The eggs were found to be practically opaque to 2537A and considerable absorption occurred before retardation was evident; the protoplasm of the egg must therefore possess considerable power to repair injury resulting from absorption of such radiations.