322 A FURTHER CONTRIBUTION TO THE 
No. I was either incapable of growing in urine or had lost its vitality during 
the five weeks which had elapsed since its introduction, while Bactertum No. II 
had survived. The last appears to have been the fact; for on inoculating 
milk and Pasteur’s solution with the new bacterium, while it throve in both 
it retained the characters that it had in the urine and occasioned no viscidity 
of the milk. And further, when introduced into artificial milk, in which Bac- 
terium No. I grew so rapidly, Bacterium No. IT failed to grow at all, the fluid 
remaining unchanged for the twenty-six days during which it was kept under 
observation. 
Some other points were observed regarding Bactertum No. II which appear 
of sufficient interest to be placed on record. When first seen in the urine it 
was unbranched, and exhibited rotatory movements ; but when again observed 
two days later it was found of larger size, and often distinctly branched, see 
Plate XI, Urine, August 6, and entirely destitute of motion. On this day 
a minute drop of the urine containing the organism in this condition was intro- 
duced into a glass of turnip infusion decanted from a stock of that liquid which 
was prepared onthe 24th of February,and had then furnished the supply for twelve 
experimental glasses, but which retained its original characters as regards aspect, 
fresh odour, and faintly acid reaction, while the microscope revealed no organ- 
isms. After two days bacteria made their appearance of the characters shown in 
Plate XI, August 8, resembling those first seen in the urine in being unbranched, 
and even more active than they, with wriggling onward movement. Two days 
later the bacteria were again motionless and of larger size, and often manifestly 
branched, see Plate XI, August 10, the turnip infusion having now acquired 
a smell like that of strong turnip soup. Again four days later, the glass shade 
having lost all smell, I supposed the fermentation to be over ; but on examining 
a drop I was surprised to find that bacteria were present in abundance, but that 
all the large and branched ones had disappeared, and in their place was a progeny 
more minute than any seen before, showing sometimes the double rod form 
most characteristic of bacteria, see Plate XI, August 14, and exhibiting active 
movements of rotation and wriggling. The only explanation that suggested 
itself to my mind was that some material of limited amount in the turnip infusion 
yielded under the fermenting influence of the bacteria a volatile product (the 
same, perhaps, that caused the soupy smell) which, while it remained, exercised 
a modifying influence upon the organism, resulting in the branched and motionless 
variety, but on escaping, as indicated by the odourless state of the fluid, left 
the bacteria to return to their former shape and active movements. And this 
view was confirmed by the result of inoculating a second glass of the turnip 
infusion from the first on the 14th of August, when the bacterium had the minute 
