VI. 
BACTERIA IN CROUPOUS PNEUMONIA. 
BACILLUS OF FRIEDLANDER. 
Synonyms.—Pneumococeus (Friedlander); Bacillus pneumonia 
(Fligge). 
Obtained by Friedlander and Frobenius in pure cultures (1883) 
from the exudate into the pulmonary alveoli in cases of croup- 
ous pneumonia. Subsequent researches show that it is only present 
in asmall proportion of the cases—nine times in one hundred and 
twenty-nine cases examined by Weichselbaum, three times in seventy 
cases examined by Wolf. 
Morphology.—Short rods with rounded ends, often so short as 
; to resemble micrococci, especially in very 
OG recent cultures ; commonly united in pairs 
op 8. OO \@ or chains of four, and under certain cir- 
0 a STO) cumstances surrounded by a transparent 
2 Q capsule. The gelatinous envelope —so- 
Fic. 88.—Bacillusof Friedlinder; called capsule—is not seen in preparations 
a, from a culture; , from bloodof ~made from cultures in artificial media, but 
mouse, showingcapsule. (Fligge.) . . s a 
is very prominent in properly stained prepa- 
rations from the blood of an inoculated animal. It often has a diame- 
ter equal to or greater than that of the enclosed cell, and appears to 
consist of a substance resembling mucin, whichis soluble in water or 
dilute alcohol. Where several cells are united in a chain they may 
all be enclosed in a common envelope, or each may have its own cap- 
sule. This capsule is not peculiar to Friedlander’s bacillus, as he 
at first supposed, but is found in other bacilli and also in the writer’s 
Micrococcus Pasteuri. 
Friedlander’s bacillus stains readily with the aniline colors, but 
is decolorized by the iodine solution used in Gram’s method. In 
preparations from the blood of an inoculated animal, stained by an 
aniline color, the capsule appears as an unstained envelope surround- 
ing the stained cell, but by special treatment the capsule may also be 
stained. Friedlander’s method is as follows: The section or cover- 
