3 1 2 
Ward. — Some Thames Bacteria . 
IV. A Pseudo-bacillus 1 . (Plate XXI.) 
This occurs as irregular and often curved rods 4 x 1 in water, 
motionless, often with spore-like darker spots in them, and 
breaking up into cocci. In old gelatine-cultures only the 
cocci are found, in chains or groups, or as diplococci and 
single cells, about 1 p or a little less when stained. They 
stain by Gram’s method. 
No true endogenous spores have been found, though easily 
stained oval bodies occur in the rods as described. 
In broth the motionless rods are often slightly curved, and 
measure 2-3 x 1-1*2 ju, and grow out to short filaments 10-12 ju, 
and segmented. In some cases inflated involution forms 
occur, nearly 2 n thick. 
Plate-cultures at i2-i5°C. show in four days as raised 
yellowish-white colonies, fairly quickly growing, and already 
coalescing. The submerged ones are very opaque, yellowish 
white, not zoned. Liquefaction begins in a week, as a slight 
sinking, but does not progress (Fig. 1). 
After three months in culture, plates at 18-20° showed 
nothing to the unaided eye until the third day, but in forty- 
eight hours the J detected minute pale discs. On the third 
day just visible as white points, which under the J are greyish, 
hyaline, coarsely granular. 
On the fifth day they look like raised drops of milk, 1 mm. 
diameter, domed, opaque, glistening yellowish white. Under 
^ course, grey-yellowish, and opaque. 
On the sixth day they are 1*5— % mm., on the seventh 
2-3 mm., opaque, cream-coloured, flattened domes. On the 
ninth day 3-4 mm., shining and like drops of cream. No trace 
of sinking, though some run together when in contact. The 
peculiar glistening appearance of the colonies is due to their 
wetness — as if sweating water on the surface. 
Stab-cultures at 12-15°. In two days a raised dome-like 
button, porcellanous white, and slight yellowish dots in tunnel. 
1 Referred to as type of Group XVIII in Proc. R. S., Vol. lxi, p. 421. 
