Influence of caffeine, cysteine, hydroxyures and cycloherimide on maternal repair system operative in female Drosophila was studied using rod-X males and Oster females. The number of parental matings was kept constant. A new method of statistical analysis was employed to examine the frequency of sex-chromosome loss in these experiments. A re-analysis of published data was also done using this method. The existence of a maternal repair system was not upheld. The observed discrepancies between data reported herein and those published earlier and the possible reasons are discussed