Abstract
When the mutabile type variant of E. coli (Murase) was cultivated on the medium containing galactose, galactose fermenting daughter type variant (RT) grew beside Murase's daughter type mutabile variant (MT) . Consequently, a series of experiments were conducted by the author on the carbohydrate fermentation, various reactions, findings on tcolonies, comparisons in S-R, re-mutability, immunological properties and the comparison with MT variant and RT variant. When RT variant was compared with the original strain, M variant and MT variant, it was found to be most closely resembling to the original strain. Furthermore, it was derived from M variant which possesses different properties from the original strain. When this RT variant was cultivated in the broth for a long period of time, M variant appeared again, and the pattern of the appearance was found quite closely resembling to the case of the original strain being almost indistinguishable from each other. It is needless to state that MT and RT variants appeared again from this M variant. These M, MT and RT variants were all indistinguishable from those derived from the M variant of the original strain. Consequently, it apparently looked like a cyclic mutation phenomenon showing a revert of M variant to the original strain which again produce M variant. However, this problem is still under further investigations.
