296 Ward. — Some Thames Bacteria. 
Agar. At 20° C. a copious, thick, spreading, glistening, pure 
white streak with iridescent edges, extending to a fron- 
descent film all over in twenty-four hours. In three days 
a thick, shining, translucent, waxy, yellowish-white layer. On 
the fifth day this is a wrinkled membrane, and a white 
wrinkled veil and precipitate are seen on and in the liquid 
of drainage. 
This glassy-looking membrane is tough and lifts as 
a whole, and the microscope shows it as a dense zoogloea, 
with rodlets breaking up to cocci in Ascococcus-like masses. 
Staining with acetic acid and dahlia-violet shows that the 
capsules enclose both single rodlets and colonies (Figs. 3 
and 10). 
At 34 0 C. the growth is similar, but less rapid. In four 
days the gum-like, translucent membrane is formed, but even 
in eight days it had not covered the surface. 
In strong growths the Agar is evidently diminished in a 
few days, serving as food-material. After a week or two at 
low temperatures the corrugated membrane is renewed on 
the stripped Agar. 
Potato. In forty-eight hours, at 22 0 C. a thin, wet, spreading, 
glistening film is formed, white at the thin fimbricated spread- 
ing margins, very pale yellow inwards, and with a greyish 
cast where thickest in the centre. About the fourth day 
the thin white margin disappears, and the whole patch is 
wet and slimy (Fig. 11). 
The microscope shows that the wet sulphur-white to 
yellowish-grey slime consists of rods 1-5 to 4/ux 1 y, motion- 
less, embedded in a tough slime which draws into long 
strings on the needle. 
At 22° alcaline potato is an equally good medium with 
normal, the colour of the copious whitish slimy growth being 
perhaps less grey and more sulphur-yellow in hue. 
Artichoke at 25 0 C. A white irregular patch was formed 
in two days, and spread all over as a white film on the fourth 
day, after which no further growth was noted, even in 
fourteen days. 
