Ji 
effect throughout the tube. A very strong pungent odour suggesting an amine 
was characteristic of these cultures. Tanner?? has described a similar effect 
produced upon litmus milk by one group of his green fluorescent water bacteria. 
His organisms, however, seem to have differed in other particulars from those 
described here. They differed, for instance, in their action upon sucrose. 
Migula has described a form known.as Pseudomonas sericea as producing alkali 
and reducing litmus—though he has classified this organism among non-fluores- 
cent forms. In the group under consideration fluorescence, observed chiefly 
in milk but occasionally upon agar and broth, seemed the only important varia- 
tion from the type described by Migula. Therefore, the tentative name of 
Pseudomonas sericea fluorescens has been given. 
4. Pseudomonas liquefaciens (Tataroff. Migula) var. marina. 
Stained with Loeffler’s methylene blue this organism appeared as a short 
rod, very often occurring in pairs. In a hanging drop it had a dodging and 
darting rapid movement in a narrow field. It possessed one polar flagellum, 
two or three times the length of the organism. It was gram-negative. 
On Gelatin Plates. 
Colonies appeared in three days, first as round white points with a somewhat 
cloudy margin. Under the microscope, surface colonies were circular, granular, 
dense in the centre with radiating, cochleate filaments from the margin. The 
deep-set colonies had a sunburst appearance, the processes, which were very 
numerous and tangled, radiating in all directions. 
On Agar Plates. 
Growth was evident in 24 hours. Surface colonies were round, moist, 
raised, cream-coloured, 1 to 2 mm. in diameter, later widening to 15 mm. Micro- 
scopically, they were grumose, concentric, dense in the centre, with successively 
thinner rings outside. Deep-set colonies were dense, disc-shaped, tilted, 0.5 to 
1.0 mm. in diameter. Magnified they appeared dark brown, grumose, with 
rough edges. 
In gelatin stab cultures liquefaction was at first crateriform. A cloudy 
appearance was produced along the line of inoculation by numerous, minute, 
discrete colonies. The margin of the liquefied area was slightly dentate. The 
liquefaction became infundibuliform about the third day and was invariably 
complete in ten days. The sediment was cream-coloured, viscid and 
abundant. 
Nutrient broth was rendered uniformly turbid with a frosty membranous 
pellicle and a sediment. 
Litmus milk became alkaline with reduction of litmus and digestion of 
casein. In this medium growth was very slow in all cases. Tested soon after 
isolation and grown in the dark the organism produced a change in the milk 
on the sixth day. In later cultures, grown at room temperature without pro- 
tection from light, no change was apparent for four weeks, after which alkalinity, 
reduction of litmus, and digestion of casein were observed. Preparations in 
plain milk gave parallel results. A strong ammoniacal odour was characteristic 
of old cultures. 
On potato no growth was obtained, though repeated cultures were made. 
One vigorous strain, however, which grew more rapidly and luxuriantly than 
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