288 
Ward.— Some Thames Bacteria . 
On plates at 12-15° C. it grows slowly as white, somewhat 
typhoid-like irregularly circular fronds, beautifully zoned and 
marked with radial lines. Under the J obj. these are contoured, 
hyaline at the edges, and yellower in the thicker, central 
portion. There are no pronounced blue or green sheens or 
iridescence, but after a week or so the fronds appear dull 
(matt), and like thin drops of stearine with irregularly contoured 
edges (Fig. 2). No liquefaction even after two to three months. 
Plates at 20° showed in forty-eight hours as white discs, like 
flattened milk-drops, 1-2 mm. diam. Under the § these are 
yellowish, contoured and opaque, the submerged colonies 
being very granular. 
On the third day the diam. = 2-5 mm., and with the typical 
opaque, stearine-like appearance. 
Fourth day = 9 mm. diam., and similar appearance. On 
holding up to the light a beautiful shagreen-like appearance, 
bossed in the centre, edges like ground glass. 
Sixth day =15 mm., opaque. Indented edges to the other- 
wise circular frond. Traces of zones and radial structure 
in some. 
Fourteenth day = 20 mm., zoned and radiate and with 
elegantly indented edges. Yellowish. 
Microscopic cultures in hanging-drops of gelatine were 
made, but it was found to be impossible to measure the 
growth. The short rodlets break up as soon as division is 
completed, and fall apart to make the colony of cocci. Fig. 3 
shows a case where the isolated rodlet (a) in gelatine at 20° C., 
at 3 p. m. had divided into two, and one of these was 
dividing again at 10 p.m. (b). At 11 a.m. next day a colony, 
oval, pale, and with the normal characters, had formed, 
measuring 99 x 85 fi in length and breadth, and several rodlets 
thick (c). 
If it was ten rodlets thick, such a colony reckoned as 
a rectangular one would contain about 
99 x 85 x jo 
= 42P75 
rodlets, which indicates fairly rapid rate of growth. 
At the same hour (11 a.m.) the following day the colony 
