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stripe-culture as an expression of its haemodigestive power. Even 
choleravibrios that influence the blood-agar-plate exceedingly slowly, 
are able to form a halo on the blood-bile plate. I tried this halo- 
formation of the choleravibrio on the blood-bile-agar plate by means 
of the gelatine-stripe method and compared this one with the halos 
on blood plates and casein plates. 
The result of these experiments which I made with several new 
and old cholera strains of a very divergent haemodigestive character, 
is shown half schematically in the following figures. 
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Fig. 1. Fig. 2. 
Fig. 1. The virtual (white dotted) gelatine-liquefying halo lies 
considerably beyond the halo of the haemodigestion on the blood- 
agar plate. 
Fig. 2. The zones approach each other very clearly on the oxy- 
haemoglobin plate; in some cases (as is shown on the figure) there 
is already an indication of transformation of the oxyhaemoglobin, 
whose line of demarcation is congruent with the halo of the gela- 
tine-liquefaction. 
Fig. 3. The halos of further oxyhaemoglobin transformation and 
gelatine-liquefaction are quite congruent on the blood-bile-agar plate, 
a condition which agrees with that on the casein plate. (Fig. 4). 
By this fact the identity of the oxyhaemoglobin-digestive, casein- 
digestive and gelatine-liquefying ferment of the cholera vibrio is 
confirmed. 
There is this profitable difference between the blood-bile-agar plate 
and the blood-agar plate, that the process of haemolysis does not 
take place in the former. 
