2 10 
Ward. — Thames Bacteria , III. 
Fig. 20. At 8.20 p.m. the ring a was lying some distance 
away — to the left — from a peripheral lobe, not shown in 
a to k , and the outline sketches a to h were made at intervals 
of a minute. 
It was evident that this ring was made up of a series of 
parallel, or nearly parallel, coiled series of Bacteria, and 
from 8.20 to 8.28 (under Zeiss B. occ. 4) these coils were 
revolving from left to right as one faces the ring, sliding 
one over the other more or less regularly and smoothly — as 
was quite clear by watching the notch-like free ends depicted 
in the inner and outer outlines. At the same time the flat 
mass of these coils was surging from side to side, sometimes 
widening, sometimes narrowing the ring. The movements 
of the ring as a whole had a curious resemblance to those 
of a smoke-ring — a vortex-ring. Between 8.28 and 8.31, 
however, the direction of revolution of the coils was reversed , 
as seen by the arrows in i to l. 
I was curious to see how stable this ring was [for although 
it often thinned out dangerously at some part ( d and g) it 
never broke] as compared with other free groups (e. g. those 
in Fig. 18), and should have watched it as long as possible, 
but at 8.39 the large lobe (to the right of b ) referred to 
above had crept nearer and nearer, and between 8.41 and 
8.42 it came into contact with and soon ( 0 , A q ) fused 
with the ring, which now became merely a part of the 
lobe. 
These illustrations will suffice to show how the progress 
of the coronal film is effected radially over the surface of 
the gelatine. The pseudopodia go on creeping outwards, 
and occasionally long tongue-like processes shoot out, and 
bits of these separate off as outlying free colonies, which 
may again join one to another or to the main corona as they 
wander over the surface, and it is these outliers and the all 
but invisible coronal film which so mysteriously liquefy the 
surface of the gelatine. In fact, at the very time I thought 
the visible colonies were extending so slowly that the 
gelatine could not liquefy before morning, the surface of the 
