STUDIES ON X-AGENT

I. CHANGE IN THE GROWTH-RATE OF PROTEUS VULGARIS DUE TO INOCULATION TIME

Abstract

Proteus vulgaris cultured in peptone solution showed growth rates which were different depending on the time it was inoculated. Culture inoculated in the morning achieved almost constantly better growth than that inoculated in the evening. In contrast to the growth, the production of NH₃-dissociable substance was lower in the group inoculated in the morning than that in the evening.
Both the rate of growth and the production of NH₃-dissociable substance of the organism underwent considerable change from day to day. The change was gradual towards one direction, probably a seasonal change, with definte fluctuations whose periods appeared mostly to be of a few days. Thus, the quantity or/and the quality of the agent concerned in this phenomenon seemed to change not only with night and day but also day after day, presumably changing with the season.