Ward . — Thames Bacteria , ///. 
2 1 1 
latter was already covered with these wandering colonies 
and outliers, and with a tenuous all but invisible reticulate 
film of Bacteria. 
The next question that arose was as to the mechanism 
of the movements of the pseudopodial-lobes, &c. ; and to 
solve this I tried to cultivate the colonies in gelatine-drops 
under the T Vth immersion. 
The series in Fig. 21 is a good one. The gelatine-drop 
was made at 11 a.m. and a rod a fixed : temp. — 2Q°C. At 
4 p.m. there were about eight rods in a clump b, and at 8 p.m. 
an oval colony 8x4 y. At 9.30, the temperature having 
fallen to 19 0 , the colony measured 10 x 8 /x, and at 11.10 p.m. 
12X10 y: temp. = 18.5V 
The temperature fell to 16 0 during the night, and at 8 a.m. 
the colony was circular and consisted of short rodlets closely 
packed and perfectly quiescent. Diameters 34 x 32 /x. At 
9.30 a.m. it was a circle 36 \ u diameter, temp. = 1 7.5 0 , and through 
the day it slowly grew as follows : — 
temp. = 1 9-5° 
10.55 a.m. 44 p 
12 noon 59 /x 
3.30 p.m. 64 /x 
8.40 p.m. 72 /x 
20 - 5 ° 
21 - 0 ° 
At 3.30 next day the hitherto granular circle was showing 
signs of differentiation ( e ). It was very opaque — really 
a sphere — but one could make out several curved filaments 
among the rest. At 6 p.m. the sphere was much clearer, 
and had evidently become looser, and the presence of 
numerous long curved filaments was observed (/), though 
no movement was discernible. I am strongly of opinion 
that the clarifying of these spheres is due to a slow increase 
of a slime between the cells, no doubt the swollen cell-walls. 
At 8.40 the clarification was more marked, especially in 
the middle, and slow writhing movements of the filaments 
and rods could be detected, the nature of which suggested 
the existence of a sort of zoogloea-slime as the medium 
in which they were occurring. 
