ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
227 
Pigment-bacteria.* — Herr A. Overbeck describes two coloured 
microbes, Micrococcus rhodochrous from tbe stomach of a goose, and M. 
erythromyxa , from the conduit- water of Halle. The colouring matter 
of both appears to be a red lipochrome ; both are aerobic. 
Photobacterium javanense.f — Herr C. Eijkmann describes a new 
kind of light bacterium, Photobacterium javanense , which at first forms 
separate luminous points on sea-fish, but in a few hours developes 
so rapidly that the whole surface is covered, and letters may be read at 
the distance of a few decimetres. Grown in 3 per cent, sugar solution 
these bacteria are mobile rodlets, with rounded ends, are from 0*8-1 p 
broad, and twice to four times as long. Some are so short that they 
resemble micrococci, while others are much longer and are made up of 
two or more rodlets. Spore-formation was not observed. Movements took 
place in curved lines. The flagella were stained by Loeffler’s method. 
These were found at one end, and much exceeded the rods themselves in 
length. Photobacterium javanense does not liquefy gelatin, and on plates 
forms circular sharply defined colonies with dark centres and margins. 
These tend to form secondary colonies which gradually become incor- 
porated with the parent colony. The colour of the light is blue-^reen 
to whitish, the spectrum extends from yellow-green to violet, the greatest 
light strength being between the lines E and the middle of E and G. 
The light is most intense in from 6-12 hours after the formation of the 
colony, and in 2-3 days there is considerable diminution in intensity. 
The optimum temperature is between 28° and 38°, but the organism 
thrives at 15°. The presence of oxygen exerts considerable influence on 
the development on a free surface, but growth takes place even in an 
atmosphere of hydrogen, though here the development of light ceases. 
The optimum temperature for light development is between 25° and 33°, 
but its actual limits are — 20° and -f- 45°. Phosphorescence ceases if 
the temperature be raised to 50°, but returns on cooling, though five 
minutes’ heating to 60° kills the bacteria completely. When cultivated 
at 47° *5 the growth proceeds with vigour, but phosphorescence ceases, 
not to be revived on cooling. 
Photobacterium javanense is distinguished from other non-liquefying 
luminous bacteria, e. g. P. phosphor escens , P. Pfliigeri, P. pathogenicum , 
by its lively movements and by its adaptability to a higher temperature. 
The latter species give out most light at 10°-15°, P. javanense at 
20°-33°. In this respect P. javanense more resembles P. indicum, which 
is distinguished by its blue-white phosphorescence and by its power of 
liquefying gelatin. 
Pigment of Micrococcus prodigiosus.J— Mr. A. B. Griffiths has 
separated the blood-red pigment of this organism grown on potatoes. 
It can be obtained simply by dissolving in alcohol, and gives the 
empirical formula C 38 H 56 N0 5 . 
Microbicidic Action of Carbon Dioxide. § — MM. C. Noury and 
C. Michel find that, contrary to the usual opinion, if milk is saturated 
* Nova Acta K. Leopold-Carol. Akad. Naturf., lv. (1892) pp. 399-416 
f Tijdschr. v. Nederlandsch-Indie, Deel xxxii. Aflevering 4, Batav. Noordwiik 
1892, pp. 109-15. See Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) p 656 J ’ 
x Comptes Rendus, cxv. (1892) pp. 321-2. § Tom. cit., pp 959-60 
