9 
mentioned in the detailed descriptions below, which rather aim to point out 
distinguishing traits. 
ORGANISMS IDENTIFIED. 
1. Pseudomonas fluorescens (Fliigge) Migula. 
The organism was easily stained and appeared as a rod of medium size 
with rounded ends, which usually occurred in pairs. Six flagella were observed 
in the polar bundle. On gelatin plates the colonies appeared after two days as 
round centres of liquefaction. A white mass of bacteria occupied the centre of 
the depression which was cup-shaped. Deep colonies were white with shadowy 
margins which, as the microscope revealed, were made up of radiating hairs. 
In the gelatin stab cultures, the line of inoculation showed a trace of lique- 
faction after 24 hours. In 36 hours its margin was clouded by numerous dis- 
crete, white, punctate colonies. At the same time a crateriform liquefaction 
had developed on the surface, with a white film lining the depression. The 
liquefaction soon became infundibuliform and the medium acquired a distinct 
fluorescence. 
On potato a dirty-greyish growth appeared after 24 hours. Though dull 
at first it became moist, spreading and shining, deepening in colour to fawn. 
The potato was at the same time darkened to brown. 
Broth was rendered turbid with a strong yellow-green fluorescence and a 
membranous shining pellicle. 
Diastatic action on starch was positive. 
On agar slants the growth was of a yellowish-grey colour, moist, shining and 
spreading, the subtratum becoming distinctly fluorescent. : 
In litmus milk the reaction was distinctly alkaline after 24 hours, the blue 
colour deepening for a week, then remaining constant; even at the end of 6 weeks 
no digestion was observable. A white shining pellicle was produced on all 
liquid media. 
2. Pseudomonas Jaegeri (Migula). 
This organism was somewhat variable in form. As a rule, it was a short 
thick rod with rounded ends. Flagella were difficult to count; in many cases they 
were turned back and formed loops along the sides of the organism. In one 
instance two were plainly observed, attached at one pole. 
On gelatin plates, round, creamy-white, zoned colonies developed within 
two days. They produced a crateriform liquefaction with a dense white mass 
in the centre. Outside this lay white turbid zones, concentrically arranged and 
becoming gradually thinner toward the margin. Under the microscope the 
small dew-drop-like colonies appeared round, finely granular and light brown. 
The larger colonies had a dense, dark brown central nucleus surrounded by a 
coarsely-granular zone, outside of which was a finely-granular area with a ciliated 
margin. 
Gelatin stab cultures rapidly became saccate and uniformly turbid. In 
96 hours liquefaction was complete. On the surface of the liquefied gelatin a 
‘light flocculent pellicle was formed and a heavy, creamy sediment lay in the 
bottom of the test tube. 
Growth on agar plates was characteristic of the old genus, Proteus. The 
9 
