442 The Botanical Gazette. [December, 
artificial media for considerable time shows that this condi- 
tion is not exceptional. It is another instance that goes to e 
show how intimate the relation is between the organism and — 
its environment; how that by modification of exterior sur 
roundings, such a deep seated phenomenon as that of repro- 
duction may be profoundly affected. a 
The chromogenic function of this bacillus is best seen when 
grown on an agar medium. On this substratum, it presents a 
fairly copious growth, smooth and shining. At first the coloris 
but slightly developed, but as the culture increases in age, — 
it passes from an ochreous yellow to a deep rich orange. There 
is considerable variation in the production of the pigment de- 
pending upon the temperature at which the culture is grown. 
Cultures kept at blood heat remain very pale and do not de- | 
velop, even in old age, the rich orange tint that is seen 
growths kept at the temperature of the room. . 
In gelatin the growth characters are as follows: In tube 
cultures 24 hours old, there is a slight pit observable at ees 
point of inoculation caused by the liquefaction of the ge sé 
tin. This spreads superficially, and also gradually — 
until there is a broad liquefied funnel formed in the ond ‘ 
that slowly widens until the sides of the tube are reac oe i 
Usually there persists for several days at the surface, wee : 
pit in the medium, caused by the evaporation of ee 4 
material. The consistency of this liquid mass is t pie 
not viscous. The fluid gelatin is filled with a slightly idee 
lent precipitate that remains in suspension, while a¢ , hae 
able amount of amorphous yellowish growth maters® rface of 
posited on bottom. | No membrane is formed on the si ‘ 
the fluid. . | 
The appearance of colonies in gelatin plates pa : 
cially characteristic. The germs quickly liquefy me e of the 
in a regular circular form. Macroscopically, the es 
colony is translucent while opaque patches of 
the center. These are usually of a 
are sometimes tinged with a faint red 
served in reflected light. | Under the lens, a 
colony is granular, the extreme periphery being sf 
Short irregular filaments radiate from the extrem ; 
the surrounding gelatin. | ; gh not very 
On agar, he ies develops quite rapidly em e as 3 
luxuriantly. The culture appears on the seco 
the densest 
dge int? 
