A Maximum Point in an Effect of Prolonged X-Ray Irradiation Upon Drosophila Larvae

Abstract

Evidence presented in a previous report showed that the mean prepupal period (the interval, expressed in days, between the laying of Drosophila eggs and the formation of the pupa), is an increasing function of irradiation. Different lots of larvae were irradiated from 35 to 245 min. by intervals of 35 min. The maximum prolongation of the prepupal period was produced by the interval 35-105 min. A decline followed by the attainment of a level plateau resulted from greater exposures.