ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
251 
Microc. tetragenus, B. pneumoniae Friedliinder, B. pseudopneumonicus 
Passet, B. capsulatus Pfeiffer. 
Bacillus rubellus.* — Dr. K. Okada gives details of a micro- 
organism, which, like the pathogenic bacillus noticed in this Journal, 
1891, p. 513, was obtained from floor-dust. The distinguishing feature 
of this bacillus is that it produces a reddish pigment, whence its name 
B. rubellus. 
Morphologically it resembles somewhat the bacillus of malignant 
oedema. Its ends are slightly rounded ; usually two or three rodlets 
are united and sometimes filaments 10-15 g are formed. 
Very active movements were observed in hanging drop cultivations, 
and the flagella were demonstrated by Loeffler’s method at one or both 
poles. The spores, which are endogenous, resist considerably heat 
and chemical agents. The bacillus is stainable with the ordinary anilin 
dyes and also by Gram’s method. This chromogenic bacillus is itself 
colourless and is non-pathogenic. It was cultivated on the usual 
media (gelatin-agar-bouillon) but only grew in the absence of oxygen. 
The appearances of gelatin and agar tube cultivations are depicted in 
coloured illustrations. 
Anaerobic Bacillus of Panic Fermentation.!— Herr M. Popoff de- 
scribes an anaerobic bacillus in cultures from dough made in vacuum or 
in air destitute of oxygen. It has the form of short rods with rounded 
ends, does not form spores, and resembles Peters’s bacillus A ; it can also 
live aerobically. It produces lactic acid, and causes the ordinary 
phenomena of panic fermentation in dough. 
Potato Disease and its Cause.J — Herr E. Kramer has, by the aid of 
bacteriology, attempted to ascertain the cause of potato blight. Previous 
observers had assigned the disease to the anaerobic organism Bacillus 
amylobacter ( Clostridium butyricum Prazm.), but the author finds that 
an aerobic bacterium, which liquefies gelatin with great rapidity, is the 
cause. The bacillus of potato rot is a rodlet 2'5 to 4 g long and O' 7 to 
0 • 8 g. broad, having rounded ends and exhibiting lively movements. In 
old cultivations endogenous spore-formation is observed. 
The bacillus presented on agar and gelatin characteristic appearances, 
the latter being liquefied, and if stained with carminic acid or litmus 
the colour was discharged. In solution of dextrose to which ammonia 
or pepton and the necessary salts were added, the bacillus developed 
very strongly, giving off carbonic and butyric acids. 
From pure cultivations of the bacillus bred in potato mash extract 
to which 1 to 2 par cent, dextrose was added, inoculation experiments 
on sound tubers were made, and the results were quite satisfactory, 
showing that this organism is the only cause of the disease of the 
potato tuber. The mode of entrance of the bacillus into the tuber is 
supposed to be the result of accidental damage, or at the eyes. 
The chemical changes which the bacillus sets up in the blighted 
* Centralbl. f. Bakteriol. u. Parasitenk., xi. (1892) pp. 1-4 (1 pi.). 
t Annal. de l’lnst. Pasteur, 1890, pp. 674-6. See Bot. Centralbl., xlix. (1892) 
p. 43. 
I Oesterreich. Landwirthsch. Centralbl., i. (1891) pp. 11-26. See Bot. Centralbl., 
xlviii. (1891) pp. 58-60. 
