1901} MICROSCOPICAL JOURNAL. ee 
a“ 
fluid. According to Haffkine, when an inoculated bouil- 
lon culture is allowed to stand perfectly at rest, ona sol- 
id shelf or table, a characteristic appearance developes. 
In from twenty-four to forty-eight hours, the liquid re- 
maining limpid, fiakes appear underneath the surface, 
forming little islands of growth, which in the next twen- 
ty-four to forty-eight hours grow down into a long sta- 
lactite-like jungle, the liquid always remaining clear. In 
four or six days the islands are still more compact and so- 
lidified. If the vessel be disturbed, the islands fall like 
snow and are deposited at the bottom, leaving the liquid 
above clear. Upon the gelatin plates at 22°C. the colo- 
nies may be observed in twenty-four hours by the naked 
eye. They are pure white or yellowish white, spherical 
in the deep gelatin, flat upon the surface, and are about 
the size of a pins’ head. The gelatin is not liquefied. 
The borders of the colonies are, upon microscopic study, 
found to be sharply defined and to become more granu- 
lar as their age increases. The superficial colonies occa. 
sionally are surrounded by a fine, semi-transparent zone. 
In gelatin puncture-cultures the development is scant. 
The medium is not liquefied ; the growth takes place in 
the form of a fine duct, little points being seen on the sur- 
face, and in the line of puncture. Sometimes fine fila- 
ments project into the gelatin from the central puncture. 
Upon agar-agar the bacilli grow freely but slowly, the 
the colonies being whitish in color, with a bluish tint by 
reflected light, and first appearing to the naked eye when 
cultivated from the blood ofan infected animal, after about 
thirty-six hours incubation 37°C. Under the microscope 
they appear moist, with rounded, uneven edges. 
The small colonies are said to resemble little tufts of 
glass-wool, the larger ones have large round centres, Mi- 
croscopic examinations of the bacilli grown upon agar- 
agar, reveals the presence of long chains resembling strep- 
tococci. 
