294 Ward. — Some Thames Bacteria. 
margins. Under the J obj. the whole colony looks 
yellowish, granular, and gradually becomes more opaque in 
the centre as the frond thickens, the margins thinning out 
and paler. 
The microscopic examination also shows the colonies 
marked by irregularly and curiously contorted lines and 
streaks (Fig. i a), and scattered sets of brighter, rounded, 
sausage-shaped and vermiform areas. In the older colonies 
these are less visible in the centre, owing to the opacity as 
the colony thickens, but the zoning is found to be principally 
due to these brighter areas nearer the margins. 
The submerged colonies are yellow, granular, opaque, and 
irregularly lobed like a complex glandular acinus or salivary 
gland (Fig. i b , c). 
As the colony ages — three to four weeks — the white becomes 
tinged with a tawny hue, and a tendency to soften and sink 
into the gelatine is evident. 
Closer examination with a higher power shows that the 
bright vermiform and rounded areas are dense zoogloea 
masses embedded in the granular matrix of the colony, and 
that the glandular submerged colonies and the dark central 
part of the emerged ones are simply dense and irregularly- 
lobed zoogloeas containing the cocci and short rodlets, the 
rest of the colony consisting of irregularly and closely-crowded 
escaped cocci without any evident capsules (Fig. i d). 
These imbedded zoogloeas are so obviously similar to 
Cohn’s Ascococcus Bilrothii that I referred to them throughout 
my notes as Ascococci , but — though unfortunately we do not 
know the size of Cohn’s form — the cells seem to be larger, 
and they are certainly not permanently cocci, as will be seen 
later. 
At 20° the colonies were visible in twenty-four hours as 
minute grey points, yellowish and granular under the J-. 
A higher power (Zeiss. D) showed them already lobed and 
capsuled. On the second day they form white opaque 
irregular circles 2 mm. diam., and like milk : under the ^ 
the submerged colonies are lobed and glandular, the emerged 
