ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
121 
Microbe of Yellow Fever.* — Dr. G. M. Sternberg, wbo some years 
ago was engaged in investigating tlie origin and prevention of yellow 
fever, now identifies the Bacillus X described by him in 1889, as the 
microbe isolated by Sauarelli, and designated Bacillus icteroides. It has 
similar morphological appearances, cultural characters, and toxic effects, 
to those ascribed to B. icteroides , and it seems extremely probable that 
the author just missed being the first in the field from too much diffi- 
dence, though, of course, the methods of bacteriology have greatly 
advanced since the report was published. 
Yellow Fever and Micrococcus xanthogenicus.f — The organism 
of yellow fever described by Dr. D. Freire is a micrococcus, M. xantho- 
genicus , having a diameter of 1—2 p and two or three cilia. It has no 
special arrangement ; it is easily stained and cultivated. It is aerobic, 
liquefies gelatin, is reproduced by spores, and in winter becomes encap- 
suled. On peptonised gelose the colonies at first are white, but later 
yellow or brown. The cultures are at first highly toxic, but repeated pass- 
ages diminish their virulence. Intraperitoneal injections are followed by 
rapid emaciation, fever, dyspnoea, jaundice and sometimes epistaxis. Tre- 
panning infection is still more toxic, the animals dying in 48 hours 
with symptoms analogous to those of yellow fever, especially fatty 
degeneration of the liver and acute nephritis. 
Attenuated cultures of M. xantliogenicus reproduce in animals and 
man a mild form of yellow fever which, the author claims, confers 
immunity ; for since 1883 he has inoculated more than 13,000 persons, 
the mortality being from 4-6 per cent. 
Bacillus of Subacute Gaseous Gangrene.J — M. Ohavigny describes 
a mobile microbe much resembling B. coli, and which appears to be the 
same as that called by San Felice Bacillus pseudo-oedematis maligni. 
The bacillus was isolated from a case of wet gangrene of the leg fol- 
lowing on a simple fracture. In aerobic bouillon cultures gas is abun- 
dantly formed, and solid media (gelatin and gelose) fragmented. When 
cultivated in bouillon and in vacuo , the mobility of the bacillus becomes 
diminished and there is a tendency to form short chains. The bacillus 
is extremely pathogenic to guinea-pigs, mice, and rabbits. Injection into 
dogs produces suppuration and sloughing. By mixing cultures of this 
coliform bacillus and Staphylococcus pyogenes aureus , the effects were 
rendered more severe, though the staphylococcus toxin was found to 
interfere with the growth of the bacillus in vitro. Bouillon cultures, 
at first alkaline, become acid on the third or fourth day, and from the 
eighth regain their alkalinity. Filtered at the latter stage the cultures 
are found to contain a substance which gives rise to similar, but less 
marked, symptoms to those of living cultures. 
Pathogenic Bacillus found in the Yemen Ulcer. § — M. M. Crendi- 
ropoulo has found in the Yemen ulcer a small bacillus with rounded 
ends, mobile and easily stained. It is easily cultivated on peptonised 
bouillon. The medium soon becomes turbid, deposits in flakes, becomes 
strongly alkaline, and exhales a foetid odour. Milk is coagulated. On 
* Centralbl. Bald. u. Par., l te Abt., xxii. (1897) pp. 145-65 (1 pi.). 
t Comptes Rendus, cxxv. (1897) pp. 614-6. Cf. this Journal, 1892, p. 535. 
% Ann. Inst. Pasteur, xi. (1897) pp. 860-4. § Tom. cit., pp. 784-9. 
