Synopsis: Tests of 30 maize cultures in the Texas (cms) cytoplasm and segregating for fertility restoring genes gave a significant advantage in yield for the restored plants. Apparently normal fertiles and restored fertiles are different in productiveness. Working hypotheses are: (1) Restorer genes have a pleiotropic vigor‐producing effect, (2) The Texas cytoplasm is superior to the more common United States cytoplasms, and (3) A heterotic genotype × cytoplasm interaction was operating.