424 PATHOGENIC BACTERIA.

gelatin punctures there is no liquefaction. The growth
takes place upon the surface principally, where a grayish-
white mass slowly forms.

Upon agar-agar a grayish-white development devoid
of peculiarities occurs.

Upon potato a rather thin whitish growth may be
observed after a few days.

The bacillus grows well in milk, with the production
of an acid reaction, but without coagulation.

The organism is pathogenic for mice of all kinds,
which succumb in from one to two days when inoculated
subcutaneously, and in eight to ten or twelve days when
fed upon material containing the bacillus. The bacilli
multiply rapidly in the blood- and lymph-channels, and
cause death from a general septicemia.

Loffler expressed the opinion that this bacillus might
be of use in ridding infested premises of mice, and the
results of its use for this purpose have been highly satis-
factory. He has succeeded in ridding a field so infested
as to be useless for agricultural purposes by saturating
some bread with bouillon cultures of the bacillus and
distributing it near the holes inhabited by the mice.
The bacilli that were eaten by the mice not only killed
them, but also infected others which ate the dead bodies
of the first victims, and so the extermination progressed
until scarcely a mouse remained in the field. In discuss-
ing the practical applicability of the employment of cul-
tures of this bacillus for the destruction of field-mice,
Brunner1 calls attention to certain conditions that are
requisite for a satisfactory result, (i) It is necessary,
first of all, to attack rather extensive areas of the invaded
territory, and not to attempt to destroy the mice of a
small field into which an indefinite number of fresh
animals may immediately come from the surrounding
fields. The country-people, who are the sufferers, should
combine their efforts so as to extend the benefits widely.
(2) The preparation of the cultures is a matter of im-

1 Centralbl.f. Bakt. u Parasitenk., Jan. 19, 1898, Bd. xxiii., No. 2.