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In this way | was able to compare haemodigestion and gelatine- 
liquefaction within the group of Proteus-bacteria. 
All the Proteusstrains which | have at my disposal (e.g. some 
indol-producing representatives of Bacteriwm vulgare Hauseri, Pro- 
Fig. 3. Fig. 4. 
teus X,, of Wem and Ferix producing indo] as well and several 
representatives of the Bacterium anindologenes distinguished by me 
as a separate species) are haemolytic, that is to say, they form a 
halo of blood-agar and cause the oxyhaemoglobin to come out from 
tbe blood-broth. 
They do not all liquefy gelatine. The an-indologenic strain Pneu- 
maturia, which liquefied gelatine strongly 16 years ago, lost this 
power long ago. This strain is the only one forming no halo on the 
blood-bile agar plate. Other facts may be added to this argument 
for the conception that also within the Proteus group, oxyhaemo- 
globin-digestion and gelatine-liquefacting are caused by the same 
ferment: only the non-haemodigestive Proteus-strain does not digest 
the casein, as the others do and the liquefaction halos, constructed 
by means of the gelatine-stripe method are congruent with the halos 
of haemodigestion on the blood-bile plate. 
Moreover I mention the experiments on B. prodigiosus, a gelatine- 
liquefying coccus from the air, B. anthracis, Vibrio dunbar, all of 
them haemodigestive and liquefying the gelatine, opposed to 5. typhi, 
coli, B. paratyphi A. and B., B. pseudo-tuberculosis rodentium, 
B. dysenteriae SuiGa and Fiexner, which do not form a halo on the 
