( 520 ) 
Gelatine is melted by the strong splitting varieties, not by the weak 
ones. | 
The length of the bacterium amounts to 2-—4u 
Breadth 1—1.5 u 
The bacterium is endowed with the power of motion, and in 
liquids mostly occurs as a double bar; on solid media it sometimes 
forms strings. 
No formation of spores takes place. 
The optimum of the growth lies near + 30°. 
The optimum of its urease near + 51°. 
Ureum-splitting by the strongest species is found in the subjoined table. 
The figures denote the number of ee. '',, N.H,SO,, which are 
necessary for the neutralization of 10 ¢.c. culture-liquid. 
The culture has taken place at 43°. 
In bouillon with ureum. 
After days 1 2 3 4. 
2° , ureum 13.5 30. 45 44. 
6°/, ureum 13, 45 68 68. 
If we compare the species described here with those isolated by 
Lohnis'), they prove to agree in size and formation of a double 
colouring-matter ; striking is the difference in the power of splitting 
ureum. 
In his experiments a bacillus erythrogenes split in bouillon 2°/, 
and 5°/, ureum resp. */,, °/, and 1°/, ureum, whilst the one described 
here splits in bouillon ©°/, and 6°/, ureum resp. 1'/,°/, and 2°/,. 
The less strong species, isolated here, still split in the culture- 
liquids named '/, °/, and 1 °/, ureum respectively. 
So it is clear that the species Bacillus erythrogenes includes varieties 
of very different ureum-splitting power. 
The powerful splitters are at the same time characterized by the 
possession of tryptic enzymes. 
§ 3. Ammoniumsalts of organe acids as a carbon-source for 
ureum-splitting microbes. 
Ammoniumsalts of organic acids are in media, which at the same 
time contain ureum and anorganic salts, superior to any other com- 
pounds for the development of strong ureum-spliting microbes. 
Both the split ureum and the ammoniumearbonate of the oxidated 
1) Centr. bl. f. Bakt. Abt. XIV Bd 1905. 
