Apparent fusion of the chromatinic bodies in species of Bacillus.

demonstrate that molecular hydrogen but not molecular nitrogen inhibits the splitting of H2 from pyruvate by Clostridium pasteurianum. The effect of H2 is similar to that observed by Kubowitz (Biochem. Z., 274, 285, 1934) with Clostridium butyricum and probably merely reflects a shift in the equilibrium of the reaction. The findings were not affected by substituting argon for the helium. From the point of view of comparative biochemistry, it is of interest that Rhodospirillum rubrum differs from Clostridium pasteurianum not only in the absence of a "Kamen-Gest reaction" in the latter but also in the absence of an effect of H2 on the photoevolution of hydrogen by the photosynthetic anaerobe. The organisms are similar in that H2 does not appear to inhibit nitrogen fixation by either.