208 Ward.— Thames Bacteria , ///. 
in the form of an irregular zone with jagged and indented 
edges (Fig. 13). More careful microscopic examination 
showed that this almost invisible zone is an extremely 
tenuous film of Bacteria arranged in coils and tresses and 
lying on the surface of the gelatine in curiously lobed, 
fimbriated, flame-like and other figures, extending round the 
more visible colony. In fact, what had hitherto appeared to 
be the periphery of the colony was only the periphery of the 
denser central parts, and this extended radially for long 
distances around as the tenuous lobed film, only one 
Bacterium deep in most of its parts. But this was not the 
most wonderful part of the phenomenon. When I had 
succeeded in seeing this film by careful focussing under the 
■|rd it was possible to make out that its lobes are composed 
of the most curiously convoluted and doubled-up tresses of 
filamentous series of Bacteria. (See Figs. 19 and 22.) A very 
fair idea of the convolutions is got by saying that they are 
a good imitation of those obtained by Mr. Galton in his well- 
known finger-prints. 
While looking at this convoluted coronal film by lamp- 
light one night, I found that the lobes at the extreme 
periphery perceptibly moved, and careful focussing soon 
showed that the whole system of this coronal film is in a state 
of creeping movement, and gradually extending itself radially 
over the surface of the gelatine. 
If a lobe is carefully watched it is seen to put out processes 
like an Amoeba ; these processes thicken up, or spread out, 
or thin out into fimbriae sometimes so fine as to be nearly 
invisible, and the Bacteria of the convolutions are also seen 
sliding one over the other. Or a piece of a lobe becomes 
constricted off, and moves freely away, over the surface of 
the gelatine ; or two neighbouring pseudopodial processes 
curve over and fuse, and so on — the movements are so 
exactly like those of an Amoeba that no other term is 
applicable. 
In Figs. 17-20 I have reproduced outline-drawings, and in 
Fig. 22 more detailed drawings, of some of these movements, 
