306 Ward . — Some Thames Bacteria . 
count the cells. The group had rotated through about i8o° 
in the interval. 
At 4 p.m. the further development seen in (c) had taken 
place, and signs of loosening of the individual cells were 
evident, and at 9.50 p.m. the group was a rapidly increasing 
botryoidal mass as shown at ( d ). Next morning it was 
a loose mass of groups like Fig. 9. 
The best series, however, is the one in Fig. to, where 
I traced the whole course of development under the ^th 
immersion. The gelatine-drop was prepared at 5 p.m., and 
after allowing time to solidify, &c., the single coccus drawn 
in Fig. 10 [a) was fixed at 5.55, t = 2o°C. At 8.5 this had 
grown to the biscuit-shaped figure shown at (b), and at 11.40 
p.m., the temperature having fallen to 3 9°C., there were 
four cocci in focus (c). Whether growth had occurred in the 
plane at right-angles to the paper I could not with certainty 
determine, but was of opinion that it had. During the night 
the temperature fell to 16 0 C., but was at 18° by 9.10 a.m., 
when nine cocci were clearly visible (d), and certainly some 
existed in the depth, but I could not focus down to them. 
By noon, growth was rapidly advancing, and two groups 
of four, one of two, and some behind were visible (e) : the 
temp. = 19° C. 
At 2.10 (t.= i9°) the group was loosening (/), and this 
went on as the growth and division rapidly advanced 
(g= 4 p.m., t. = 2i°), till at 9 p.m. (t. 22°) there was a mass 
like a bunch of grapes (h). 
Plate-cultures at I2-I5°C. show slowly-developing, raised, 
dry, rose-pink points, which even after three weeks are not 
more than 1-2 mm. in diameter, and do not as a rule liquefy. 
In a week the submerged colonies, under the Jrd objective, are 
irregular, roundish, dull-pink and granular ; while the emerged 
ones are prominent, rose-pink, opaque drops, showing a deeper 
centre, and a paler granular zone around. Even after two 
months the rose-pink, slightly sunk, projecting points are not 
bigger than in three- weeks’ plates (Figs. 1-3). 
Under the frd objective the older emerged colonies show 
