ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
247 
not by phagocytosis, but only in the same power as is possessed by tho 
cells of the whole organism. The process is a chemical, rather than a 
morphological one. 
Destruction of Field Mice by means of Pathogenic Microbes.* — 
In February 1893, an epidemic of field mice was observed by M. J. 
Danysz at Charny, Seine-et-Marne, and on bacteriological examination, 
the constant presence of a micro-organism in the organs and secretions 
of the body was revealed. 
The organism, when stained by Gram’s method, was seen to be a 
small bacillus with rounded ends, the polar points often being more 
deeply coloured. It developed well and quickly on the usual cultivation 
media, though agar, on the surface of which it spread in a uniform 
yellowish-grey layer, seemed to suit it best. 
Inoculated on healthy mice ( Mus arvalis and M. sylvaticus) it gave 
rise to the same disorder as the natural disease, and all the animals 
died. Inoculation experiments showing that it was not pathogenic 
to other animals such as poultry, cats, dogs, and cattle, it was deter- 
mined to attempt the destruction of small rodents in a district much in- 
fested and ravaged by them. 
Twenty agar tube cultivations, 5-6 days old, were mixed with 
50 litres of water and about 80,000 pieces of bread 1 ccm. square were 
soaked therein. One piece of bread was placed close to every sixth 
hole. Three days afterwards the fields were found strewn with the 
dying and dead bodies of mice. 
Vibrio resembling Cholera Bacillus.f — Dr. F. Kiessling isolated 
from a sample of water sent from the Altona waterworks a vibrio having 
some resemblance to the cholera bacillus. The water was suspected 
because, a few yards from it, four persons had died of cholera. The 
vibrio is a plump rodlet with rounded ends, 1 * 5-2 * 0 ^ long and 0 • 6 /x 
thick. At room-temperature it is slightly curved and exhibits well- 
marked comma-forms. When incubated involution forms are frequent. 
There is a flagellum at one end. Between this organism and the cholera 
vibrio are well-marked differences. It grows but slowly in neutral pep- 
ton solution. There is no growth visible to the naked eye on potato. It 
does not give the cholera red reaction. 
Vibrio danubicus.l — Dr. A. Heider describes a vibrio which was 
isolated from Danube water, having characters extremely like that 
of the cholera bacillus. In young cultures the comma form having a 
moderate curve and rounded ends is far more frequent than the sigma- 
shape, while in the older cultivations long screw-like forms are seen. 
In short, the morphological characters vary with the age of the culture 
and the composition of the medium, natural or artificial. In hanging 
drops lively movements are visible, the motile organ being a flagellum 
1 J times as long as the vibrio, with two or three turns ; each individual 
possesses one flagellum at one pole. On gelatin plates this vibrio grows 
quickly, and in the earlier stages the colonies are remarkably like those 
* Comptes Rendus, cxvii, (1893) pp. 869-72. 
t Albeit. Kaiserl. Gesundheitsamte, iii. (1893) pp. 430-8. See Centralbl. f. Bak- 
teriol. u. Parasiteuk., xiv. (1893) pp. 776-9. 
X Centralbl. f. Bakteriol. u. Parasitenk., xiv. (1893) pp. 341-57. 
