Ward —Some Thames Bacteria. 313 
In a week the colony above is a pure white, much raised, and 
shining like wet glazed porcelain. In a month it becomes 
cream-like and soft. 
At 20 0 it grows equally well on acid and alkaline gelatine. 
In three days it is a very white raised button, 2-3 mm., with 
slightly confluent dots in tunnel. On the fourth day it is like 
porcelain, thick, glistening, raised. After about the sixth day 
it acquires concentric zones and a cream-colour, and looks as 
if turned (terraced) out of cream-coloured porcelain. No 
liquefaction, even in ten weeks. 
Streak-culture at 20°. Cream-coloured, raised, glistening 
streak in forty-eight hours, and this grows fairly rapidly (Fig. 
9). In a week it is a thick, glistening, creamy porcelain-like 
patch, broader below. No liquefaction in two months. 
Agar at 30°. Forms a feeble streak, very thin, which makes 
no progress after forty-eight hours, but fades out as a trans- 
parent film. Invisible in eight days. At 35 0 also no growth 
in five days, whereas cultures at the same time at 23-25 0 
formed a milk-like, broad, thin, shining, gummy or waxy 
streak with dense yellowish-white deposit all through the 
drainage (Fig. 10). 
Potato at 22 0 . In twenty-four hours a wet spot, like dew. 
In three days this is a diffuse thin streak like milk and water. 
It thickens on the fourth day to a grey paste, and in a week 
is a not very extensive patch of cream-like, flesh-coloured 
paste (Fig. 8). On normal potato the growth is much more 
raised and distinctly flesh-coloured than on alkaline potato, 
perhaps because the potato acquires a pale violet hue showing 
it up. In ten days or so, both cultures are like rich buff or 
flesh-coloured cream. 
At 34 0 the growth fails. A dew-like patch forms at first, 
but shows no advance in six days. 
But on keeping the tube at lower temperatures, the 
characteristic flowing cream-like patch forms after some time. 
Broth at 25 0 shows traces of turbidity in forty-eight hours, 
and a slight deposit in three days. On the fifth day a copious 
yellowish-white deposit. In a week, still turbid and a white 
