BACTERIUM SYNCYANEUM. 289 



constant. Compare also Lesage (C. B. in, 8, and iv, 135) regarding 

 the Bacterium of green diarrheas. 



The same experience occurred to us with the Spirillum fluorescens 

 of Krai. It corresponded exactly upon all nutrient media with the 

 Bact. putidum ; microscopically it presented rods with a single flagel- 

 lum, 0.4-0.6 /J. thick and 0.8-3 // long. We may here add that it may 

 sometimes be very difficult to reach a certain decision as to whether 

 we have to deal with a vibrio with a single flagellum, or a member of 

 the fluorescent group with single flagella, since there occur almost 

 straight vibrios as well as bent rods. At any rate, the fluorescent 

 group forms the transition to the vibrios. The following appears to 

 belong in this connection : 



Bacterium denitrificans. Stutzer and Burri. 



(L. and N.) 



Bacillus denitrificans I. Stutzer and Burri. Liberates gaseous ni- 

 trogen from nitrite, and from nitrate only when reducing bacteria 

 (Bact. coli and others) are present. For details regarding this inter- 

 esting organism, see C. B. L. I, 257, and Weissenberg (A. H. xxx, 



274). 



Bacterium syncyaneum. (Ehrenb.) Lehm. 

 and Neum. 



(Plates 27 and 28.) 



Literature. Hiippe (Mitt. a. d. Gesundheitsamt II, 355), Heim 

 (A. G. A. V, 518), Thum (A. K. I, 291). 



Synonyms. Bacillus cyanogenes Fliigge, Pseudomo- 

 nas syncyanea Migula. Bacillus of blue milk. 



Microscopic Appearance. Small rods, with blunt or 

 pointed ends, 0.5/x thick, 1.23^ long. Threads could not 

 be seen (27, vn). 



Motility. Active motion dependent upon from 1 to 5 

 flagella at one pole, rarely (before division) upon bipolar 

 flagella (27, vm). 



Staining Properties. With anilin dyes and by Gram's 

 method. In staining plasmolysis sometimes occurs, so 

 that the bacteria have stripes like a zebra. 



Requirements as to Temperature, Nutrient Media, 

 and Oxygen. Obligate aerobe, grows best at room tem- 

 perature, perceptibly less at 30, and at 40 it soon dies. 

 .It grows w r ith moderate rapidity. 



Gelatin Plate. (a) Natural size. Deep: Roundish 

 19 



