Besides, the fact that the Fl hybrids of these inbred lines lack such meiotic abnormalities and resemble the original population almost amounts to the establishment of the genotypic control of chromosome behaviour during meiosis. This 'normalization of meiosis' in the hybrid plants must be related with their genetically balanced condition. Whether these chromosome characters also segregate is not known at present; only a further cytological study of F2 interlinear hybrids may provide the answer.