350 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
to account for it, inasmuch as the milk cultures of M. casei amari con 
tain hitter bodies which do not belong to the peptones. 
Bacillus liquefaciens lactis amari sp. n. was isolated from bitter 
cream. It is mobile and liquefies gelatin on plates, on which it forms 
round yellowish finely granular colonies. On potato it forms a thick 
film, which with age becomes whitish. Bouillon becomes turbid. Its 
dimensions are very variable, sometimes being short and coccoid, at 
others 5-6 /x long, the average joints being 1-1 • 5 /x long by 0 • 5 /x broad. 
On potato the ovoid form predominates. It coagulates milk without 
acidifying it ; hence the coagulation is due to the formation of a rennet. 
At the outset the taste of the milk is sweetish, but in 48 hours it be- 
comes bitter. Fresh sterilised cheese, when inoculated with this 
bacillus, becomes grey and acquires a disagreeable and bitter flavour. 
This bacillus grows well at room temperature, but better still at 
incubation heat. Its resistance to physical and chemical agents is 
feeble. It does, not, apparently, possess any pathogenic action. 
Bacteria of the Mouth.* — Herr E. Rosenthal isolated from the 
mouth five hitherto undescribed species of microbe : — 
(1) Sarcina viridis flav&scens chiefly occurs in tetrads, the individual 
cells having a diameter of 0*75-1 fx. Gelatin is liquefied, and on agar 
at 18°-20° C. is formed a luxuriant greenish-yellow overlay with irregu- 
larly indented edges. On potato a broad dry streak of a greenish- 
yellow hue appears. It does not form spores, requires oxygen for its 
proper development, stains with Gram, but best with methylen-blue. 
(2) Micrococcus Beessii ; round cocci of 1-2 /x diameter ; singly, in 
pairs, tetrads, chains, and groups, devoid of movement. Gelatin is lique- 
fied extremely slowly. On agar or milk, copious growth at 37° *5. On 
potato, at 18°-20°, the growth is similar. Does not form spores ; is a 
potential anaerobe. Stains well. 
(3) Micrococcus ochraceus ; round or slightly oval cells 0*8-1 *2 /x 
in diameter, arranged much like the last. Devoid of movement. 
Gelatin is not liquefied. Quickly forms on agar at 18°-20° a shiny 
greyish- white overlay ; on potato the streak is a dull yellow ochre ; 
spore formation not observed ; a potential anaerobe. Stains well. 
(4) Dijplococcus Hauseri ; spherical and ellipsoidal cells of 0*8-1 *4 /x 
in diameter ; without movement. Gelatin is not liquefied. On agar, at 
room and incubation temperatures, a mucoid yellowish-grey overlay is 
formed. On potato the appearances are similar. No spores are formed ; 
is a potential anaerobe. Stains easily. 
(5) Bacterium cercisinum ; oval to ellipsoidal cells 0 * 9-1 * 4 /x long and 
0 * 7-0 * 9 /x broad ; occurs singly, or in pairs or groups. Does not liquefy 
gelatin. On agar, at 35°-37°, forms a cherry or brick-red, smooth, bright 
deposit. On potato, at 18°-20°, a broad, dry, cherry-red streak appears 
moderately quickly. Spore-formation was not observed. Requires 
oxygen for its proper development. Stains well. 
Streptococci of the Mouth.f — MM. F. Widal and F. Besancon have 
examined the Streptococci found in the healthy mouth, and also those 
* Inaug.-Diss., Erlangen, 1893. See Centralbl. f. Bakteriol. u. Parasitenk., xvi. 
(1894) pp. 1024-5. 
t Rev. Trimestrielle Suisse d’Odontologie, 1894, p. 185. See Centralbl. f. Bak- 
teriol. u. Parasitenk, xvi. (1894) pp. 1060-1. 
