6 2 Ward. — A Violet Bacillus from the Thames. 
occurred. The water having evaporated, the colonies are 
flattened on to the glass. 
In stab-cultures in gelatine a white, button-like mass forms 
at the infection-point in three days at 15 0 C., while minute 
points develop along the line of inoculation. In ten days 
a thistle-head funnel of liquefaction is developed, still all 
quite white. In eighteen days the liquefaction at the top has 
reached the walls of the tube, or nearly so, and the liquefied 
gelatine above -is found to have a dense, tough membrane on 
its surface, the white matrix of which is turning purple. 
This membrane (zoogloea) lines the sides of the funnel-shaped 
depression, as the surface of the gelatine sinks owing to 
evaporation (Fig. 7 c). 
In a month, at this temperature, the gelatine was liquefied 
about one-eighth of the distance down, and a deep violet 
zoogloea-membrane floated on the top, while violet flecks had 
fallen to the bottom of the liquid, and rested on the still solid 
gelatine below (Fig. 7 d). 
All the gelatine-tube cultures show liquefaction of the 
gelatine. The rate at which this progresses at 20° C. may be 
estimated from the following : in six days the upper one-third 
of the gelatine of a stab-culture was liquefied, and with 
a beautiful deep violet, funnel-shaped mass of the Schizomy- 
cete tailing off below into the solid gelatine. Even after three 
months the gelatine is only liquefied about two-thirds down 
the tube, and six months’ tubes may still have some gelatine 
solid below. The liquefied gelatine is very viscid. The thin 
streak in the solid gelatine was still buff in colour, apparently 
from lack of oxygen. 
Streak-cultures on gelatine, at i5°-20° C., grow fairly 
rapidly. In twenty-four hours at 1 5 0 C. a white opaque streak 
was developed, which in three days began to show traces of 
the violet pigment, and the gelatine began to soften below, so 
that the culture sank in. In nine days the gelatine was 
excavated by a large scoop-like cavity, filled with viscid liquid 
(the surface being kept flat by inclining the tube till nearly 
horizontal) on which floated a deep violet membrane, while 
