that the gas of Liborius and Schottelius was only a chemi- 

 cal product of the action of succinic acid, which B. prodigiosus 

 forms from sugar upon Na 2 C0 3 . 



My results differ from those of Scheurlen and of Ritter. 

 In standard bouillon, freed from muscle sugar by Theobald 

 Smith's method, neutralized by NaOH instead of by Na. 2 C0 3 , 

 and then having added to it iy 2 / dextrose, B. prodigiosus 

 I produced at the end of a week a bubble of gas in the fermen- 

 tation tube. Contrary to Scheurlen's observation, this did not 

 remain stationary but increased daily. 



1) 7th day 4 mm 2) 7th day bubble 



8th 7 8th 12 mm 



10th 5 10th 19 



12th 5 llth 



17th 5 



19th 



31 mm 34,5 % 



26 mm 34,5 % 



All of the gas was absorbed by NaOH, showing that the gas 

 formed was C0 2 . Fermentation of the carbohydrate must have 

 taken place, for in this case no sodium carbonate had been added 

 to the medium, from which succinic acid could set C0 2 free. The 

 end reaction of the medium was acid to litmus. 



In lactose and sucrose bouillon no gas was produced, nor did 

 any appear in asparagin-sulphate-phosphate solution to which 2 % 

 dextrose was added. 



Oxygen relations. Liborius says (loc. cit. p. 172) that 

 such facultative anaerobes as Bac. crassus sputig, Bac. 

 pneumoniae, and Proteus vulgaris, which possess the 

 power to ferment sugar, do this equally well in the presence or in 

 the absence of oxygen. "Der B a c. p r o d i g i o s u s bietet den einzigen 

 Ausnahmsfall, daB Garung nur in den sauerstofffreien Kulturen 

 eintritt; aber auch hier ist nicht etwa die Garung ein Mittei, 

 dessen sich der Pilz bedient, um bei dem SauerstoffausschluB leben 

 und wachsen zu konnen, sondern er vermag ebensowohl in luft- 

 freiem Raum zu gedeihen, wenn gar kein garfahiges Material in Nahr- 

 substrat vorhanden ist. a My results on the anaerobic life of B. pro- 

 d i g i o s u s differ from those of Liborius and agree with those 

 of Ritter. In sugar bouillon B. prodigiosus grows, without 

 pigment, in the absence of oxygen. In sugar free bouillon no 

 growth takes place, although upon admission of air after fifteen or 

 twenty days development will proceed. Liborius' results can be 

 explained by the probable presence of muscle sugar in his so-called 

 sugarfree media. As I have shown above, absence of oxygen is 

 not necessary for gas production. 



Temperature relations. B. prodigiosus develops at 

 37 1 / 2 C, but without pigment production, which is impeded at 

 a temperature of 35. Development is prevented by a tempera- 

 ture of 42 C. 



