EVOLUTION OF OXYGEN FROM COLOURED BACTERIA. 123- 
On the Evolution of Oxygert from Coloured Bacteria. By 
Atrrep James EwakKr, B.Sc., Ph.D., 1851 Exhibition 
Scholar, formerly Demonstrator of Botany in University 
College, Liverpool. (Communicated by Prof. J. REYNOLDS 
Green, D.Se., F.R.S., E.L.S.) 
[Read 15th April, 1897.] 
THE relations of Bacteria to oxygen exhibit some of the most 
interesting and important phenomena of biological science, for 
in obligate anerobic Bacteria we are confronted with plants 
the respiration of which is apparently quite different from that of 
ordinary plants or animals. An explanation of the phenomenon 
of anerobism, which has been put forward by Pasteur, is that these 
organisms have the power of holding a supply of reserve oxygen. 
This hypothesis, however, fails to explain the existence of 
anerobic Bacteria, to which the presence of only a slight amount 
of oxygen is extremely injurious. In addition, Hesse * has 
shown that anwrobic Bacteria in the absence of all free 
oxygen evolve CO, in such amount as can only be explained by 
"ipposug that the oxygen thus evolved is derived from the 
stable oxy gen containing eompounds in the nutrient medium. 
Beyerinck T, arguing from the fact that phosphorescent 
acteria may continue to show phosphorescence for an hour or 
more after all oxygen has been absorbed by sodium hyposulphite, 
conclude s that these organisms are exceptional in possessing & 
ae combined oxygen, present in sufficient amount to permit 
after ee and phosphorescence continuing for à short time 
hot, ho supply of external oxygen has been cut off. This does 
| Aowever, appear to be any reason for considering this 
à Pd to be anything more than a manifestation of what 
. cond 7 known as intramolecular respiration. Beyerinck 
continuanes of that anzrobie Bacteria require ultimately for the 
oxygen, and th their life and vegetative activity a slight store of 
to &eneration au this oxygen can be handed on from generation 
sible to detect held in such a manner its presence 18 1mpO8- 
ttle else bur and, indeed, Beyerinck's statement amounts to 
Saying that combined oxygen is a constituent of 
*R.H 
thum der " " * Ueber die gasfórmigen Stoffwechsel-Producte beim Wachs- 
axterien,” in Zeitschr, f. Hygiene, Bd. xv. 1893, p. 17. 
M. W, ; . 
Beyerinck, in Archives Néerlandaises, xxiii. pp. 416-427. 
