CHAPTER XI.
BUBONIC PLAGUE.

THE bacillus of bubonic plague (Fig. 121) seems to
have met an independent discovery at the hands of

FIG. 121.—Bacillus of bubonic plague (Yersin).

Yersin and Kitasato in the summer of 1894, during the
activity of the plague then raging at Hong-Kong. There
seems to be but little doubt that the micro-organisms
described by the two observers are identical.

In a recent study of the plague, Ogata1 states that
while Kitasato found his bacillus in the blood of cadavers,,
Yersin seldom found his bacillus in the blood, but always
in the enlarged lymphatic glands. Kitasato7 s bacillus
retains the color when stained by Gram's method; Yer-
sin's does not. Kitasato's bacillus is motile; Yersin's,
non-motile. The colonies of Kitasato's bacillus when
grown upon agar are round, irregular, grayish-white with

1 CentralbL f. Bakt. u. Parasitenk., Bd. xxi., Nos. 20 and 21, June 24,,
1897.

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