ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
347 
the fever, but resulted in acute septicaemia and death in 21-48 hours. 
Where the fever was allowed to run its course, the animals lived for 
2-4 weeks. The injurious result seems to be wholly due to a lowering 
of the febrile temperature, not to the lotion itself, nor to any toxic action. 
He regards “ the fever as a rational phenomenon favourable to the 
organism, and the heat itself as useful.” 
Vibrio Infection per os of Young Cats.'* * * § ' — Dr. E. Wiener has re- 
peated the experiments made by Metchnikoff, who failed to infect young 
cats with cholera per os. Two lots of animals were treated with cholera 
cultures of different origin. In the first lot (5) all the animals were 
affected with diarrhoea, and one died. All the second lot (6) died, the 
symptoms being cramps, diarrhoea, and fall of temperature. The prin- 
cipal anatomical appearances were hyperaemia of intestinal mucosa, with 
some epithelial desquamation and enlargement of the spleen. Vibrios 
were found in the liver and kidneys, and in large numbers in the 
blood. 
Microbes of the Indian Rivers.f — Mr. Hankin has observed that the 
Jumna and the Ganges possess the power of destroying the cholera 
microbe, apparently from the presence of certain volatile acid substances. 
In the well water of the same districts the cholera microbe flourishes 
vigorously. Only in natural conditions do the river waters retain the 
power of auto-disinfection ; for when boiled the river water was found to 
favour the multiplication of the cholera microbe. 
Black - Pigment - forming Bacillus, f — Herr W. Biel describes a 
bacillus belonging to the group of potato bacilli, its distinguishing 
character being the formation of black pigment. It is an essential 
aerobe, and its optimum temperature is from 37°-40°. The rodlets are 
straight, with rounded ends, from 2 ■ 8—3 * 6 /x long and 0*8 /x broad. They 
are easily stained with anilin dyes, and are not decolorised by Gram’s 
method. In hanging drops they exhibit lively movements, effected by 
means of lateral and polar flagella. In old cultures endogenous spores 
are formed. Inoculation experiments on animals were negative. The 
organism was successfully cultivated on the usual media, and formed 
pigment, which on bread was quite black. On the remaining media the 
colour was less intense. All the ordinary solvents failed to extract the 
pigment or to alter its tone. 
Retention of Virulence by Streptococci. § — In 1887, Prof. Axel 
Holst isolated from the cusp of a valve of a case of infectious endocar- 
ditis a streptococcus which exhibited the cultural characters of Strepto- 
coccus brevis. For more than eight years this coccus has retained its 
virulence undiminished, notwithstanding that it has been kept in ordinary 
media and at room temperature. This retention of virulence under the 
conditions stated is unusual ; for it has been laid down by previous ob- 
servers that to maintain the virulence of Streptococci they must be trans- 
ferred daily to new media, preserved in a refrigerator, or special media, 
such as ascitic fluid or serum, must be used for the cultivation. 
* Centralbl. f. Bakteriol. u. Parasitenk., l te Abt., xix. (1896) pp. 205-7. 
t Ann. Inst. Pasteur, x. (1896) pp. 175-6. 
X Centralbl. f. Bakteriol. u. Parasitenk., 2 te Abt., ii. (1896) pp. 137-40. 
§ Op. cit., l le Abt., xix. (1896) pp. 387-9. 
