Mutagenic Effect of X-rays on Moths

Abstract

WE certainly agree with Dr. Kortschak that there is a larger increase in mutation-frequency from 0–20 and 0–40 r. than would be expected from the dose-relationship at higher doses. But in his considerations he leaves out of account the very low, and repeatably low, value at 10 r., and the sentence quoted by him refers to these very low doses between 0 and 10 r., where only an insignificant effect was found. Somewhere between 10 and 20 r. there must be a steep increase in mutation-frequency, which might be a rather sudden step. The hypothesis is that there might be a protective mechanism, which is destroyed by doses between 10 and 20 r. However, this needs to be proved by extensive experiments and because of their hypothetical character these considerations were not included in the short communication.