NOT DESCRIBED IN PREVIOUS SECTIONS. 545 
tem, from green pus in the pleural cavity, from serum in the peri- 
cardial sac, and from the spleen, in pure culture. 
Martha, Gruber, Maggiora, Gradenigo, Kossel, and Rohrer have 
reported cases in which the Bacillus pyocyaneus has been obtained in 
pure cultures from pus obtained from the tympanic cavity in middle- 
ear disease. Kossel (1894) relates several cases in his own experience 
which led him to the conclusion that, in children, the Bacillus pyocy- 
aneus, through general blood infection or indirectly through the 
absorption of its toxic products, may be the cause of death. 
The following varieties of this bacillus have been described by 
bacteriologists: 
BACILLUS PYOCYANEUS  (P. Ernst). 
Found in pus from bandages colored green. 
Morphology.—Slender bacilli from 2 to 4ulong—occeasionally 5 to 6 u— 
and from 0.5 to 0.75broad ; sometimes united in pairs, or chains of three 
elements. 
Biological Characters.—An aérobic, liquefying, actively motile, chro- 
mogenic bacillus. Produces a yellowish-green pigment; when old cul- 
tures are shaken up with chloroform and this is allowed to stand, three 
layers are formed—an upper, clouded, dirty-yellow layer ; below this is a 
milky, pale-green layer ; and at the bottom a transparent, azure-blue layer. 
Spore formation has not been demonstrated. Grows in the usual culture 
media at the room temperature—more rapidly at 35°C. Upon gelatin plates 
colonies are formed resembling those of the well-known Bacillus pyocyaneus, 
but liquefaction is more rapid. In gelatin stick cultures funnel-shaped 
liquefaction occurs at the upper part of the line of puncture by the third 
day, and progresses more rapidly than is the case with Bacillus pyocyaneus 
under,.the same circumstances ; on the fifth day a bluish-green color is de- 
veloped; by the twelfth day liquefaction has obliterated the entire line of 
growth and extends to the margins of the tube; the liquefied gelatin for a 
depth of about one centimetre hasa dark emerald-green color, and a film 
consisting of bacilli isseen upon the surface. Upon the surface of agar a 
flat, greenish-white, dry layer is formed along the line of inoculation, and 
the agar around, at the end of a week, acquires a bluish-green color. Upon 
potato, at the end of three days, an abundant dry layer of a fawn-brown 
color has developed ; this is surrounded by a pale-green coloration of the 
potato, and at points where the surface is fissured, an intense dark-green 
color is developed; the growth on potato has a more or less wrinkled appear- 
ance ; when one of the fawn-colored colonies 1s touched with the platinum 
needle, the point touched, at the end of two to five minutes, acquires an in- 
tense dark leaf-green color, which reaches its maximum intensity in about 
ten minutes, and has faded out again at the end of half an hour. Ernst con- 
siders this ‘‘chameleon phenomenon” the most characteristic distinction 
between the bacillus under consideration and Bacillus pyocyaneus. In milk 
a green color is developed at the surface, the casein is precipitated and sub- 
sequently peptonized. 
Bacillus pyocyaneus pericarditidis. Found by H. C. Ernst in 
fluid obtained by tapping the pericardial sac of a man aged forty- 
seven years. Fluid was drawn from the pericardial sac on four dif- 
ferent occasions. The man subsequently “eloped.” Ernst gives the 
following description of this bacillus: 
35 
