IN SUSCEPTIBLE ANIMALS. 509 
Morphology.—Bacilli with rounded ends, about twice as long as 
broad, and one-third smaller than the bacillus of typhoid fever 
(Eberth and Schimmelbusch). The bacillus of hog cholerais shorter 
and more slender than the Marseilles bacillus, and the bacillus of 
Léffler and Schiitz is still smaller (Rietsch and Jobert). 
In stained preparations the extremities of the rods are usually 
deeply stained, while the central portion remains unstained—“ polar 
staining.” By Léffler’s method of staining the presence of flagella 
may be demonstrated (Frosch). 
Stains readily with the aniline dyes usually employed, but does 
not retain its color when treated by Gram’s method. 
_Biological Characters.—An aérobic (facultative anaérobic), 
non-liquefying, actively motile bacillus. Grows readily at the 
room temperature, and is distinguished from the bacillus of septi- 
cemia hemorrhagica by its active movements and more rapid and 
abundant development in the various culture media usually em- 
ployed. It is distinguished from the bacillus of hog cholera by pro- 
ducing phenol and indol in solutions containing peptone, by causing 
coagulation of milk, and by producing an acid reaction in this fluid. 
Grows in culture media having an acid reaction. 
Rietsch and Jobert give the following account of the characters 
of growth in various culture media, as compared with the bacillus of 
hog cholera and the bacillus of Schweineseuche (Léffler, Schutz) : 
Gelatin streak cultures. At the end of twenty-four hours this 
bacillus had developed considerably, while the growth of the hog- 
cholera bacillus was scarcely to be discerned with the naked eye, and 
the bacillus of Schweineseuche did not form a visible growth until 
the end of forty-eight hours. After several days the bacillus of 
swine plague (Marseilles) formed an opaque, yellowish-white streak, 
which, when examined with a low-power lens, had a brown color by 
transmitted light and a bluish-white color by reflected light. The 
streak of the Léffler-Schiitz bacillus was not so thick and not so 
opaque, and was made up of small, nearly transparent colonies ; the 
hog-cholera bacillus came between the other two. Upon blood 
serum, agar, and glycerin-agar the Marseilles bacillus grew more 
rapidly than the other two, forming a layer which was opaque and 
of a white color, with bluish and reddish reflections. Upon potato 
it formed a thick, opaque, yellowish layer, while the growth of the 
hog-cholera bacillus was much thinner and that of the Léffler-Schiitz 
bacillus scarcely to be seen. In bouzllon the Léffler-Schiitz bacillus, 
at the end of three days at 37° C., had not produced any perceptible 
lings and from other sources, the result was exactly the opposite—viz., a decided 
production of alkali in milk and identity with the hog-cholera bacillus of Salmon.” 
