Using eleven species of bacteria described in the preceeding paper, the author observed the fluctuation of the growth of bacteria cultured by serial transfer through ten generations on the synthetic fluid media prepared carefully its amino nitrogen contents, and investigated the fluctuation of the enzyme activity of bacteria. 1) The all species of bacteria except Staphylococcus could be cultured succesfully through ten generations on the synthetic fluid media contained simply few species of amino acids. Moreover, the cellular amount yielded was fairly abundant, so it was suitable preparation for study of its metabolism. It was observed on Sal. enteritidis and Sal. typhi murium that the growth of bacteria increased with the progress of transfers. 2) In the light of O(2)-uptake by Warburg's manometer, the author compared the enzyme activity to four substrates, i.e. glucose, lactic acid, succinic acid and glutamic acid, of the bacteria cultured in the synthetic fluid media by serial trasfers with that of the bacteria cultured normally. Generally, that activity of the former was reduced than that of the latter. But the activities of Sal. typhi 57 S and Shigella flexineri 2 a to glucose and that of Shigella sonnei to glucose and glutamic acid were risen.