Abstract
The cultivation of Stephansky's bacilli on my devised and Nakamura's media presented many bacilli at the first generation, but they decreased and disappeared at the second and the third generations. The inoculation of these bacilli to rats, to discriminate the alive from the dead, informed us that the bacilli, whicn had been recognized of a large number at the first generation, were dead after 60 days on the media. On mucin media they were not found dead till 80 days, therefore, the mucin media may keep bacilli alive longer than any other ones, but did not allow them to proliferate.