292 IMPORTANT VARIETIES OF FISSION-FUNGI. 



blue pigment, but only bacteriofluorescein, and Htippe 

 and Thumm (A. K. I, 291) have observed those which 

 produced a pure blue pigment. Finally, all chromogen- 

 esis may be lost (Heim, /. c; Behr, C. B. viii, 485). 

 Regarding syncyanin, we still know little; we have been 

 unable to find a good solvent for it; spectroscopically it 

 furnishes a powerful absorption band. Weak acids do not 

 alter the color, strong hydrochloric and sulphuric acids 

 change it to violet, acetic acid produces a dirty color. 

 Sodium hydroxid produces a rosy to yellowish red; the 

 change in color occurs as the acid reaction disappears; upon 

 standing, the color passes into brownish-red, thus explain- 

 ing the color of old cultures. 



Acid is not formed from milk-sugar, but is from grape- 

 sugar without liberation of gas. In peptone bouillon 

 no H 2 S is formed, but traces of indol are produced. The 

 bouillon smells disagreeably aromatic, and abundant am- 

 monia is formed. 



Distribution. — (a) Outside the body : Often found in 

 blue milk, sometimes occurring epidemically. Such milk 

 is not harmful, (b) In the body the organism has not 

 been found. 



Bacterium brunificans. Lehm. and Neum. 



Actively motile, does not liquefy gelatin, isolated from foul pus by 

 Scheibenzuber (C. B. VI, 441). In stab cultures upon various nutrient 

 media it discolors the medium dark brown in the form of a sack — i. e., 

 above for a short and below for a greater distance from the stab canal. 

 Upon the potato there develops a brown growth, about which is a ring 

 of dark brown discoloration. 



Bacterium ferrugineum. (Rullmann.) L. and N. 



According to the description, it is closely related to the 

 preceding. It is actively motile. Cultures yellowish or 

 reddish, but usually dark brown, with marked rusty 

 brown discoloration of the nutrient medium. Pigment is 

 soluble in water, alcohol, and acetone. Upon meat infu 

 sion-glycerin-agar there is, at 37°, a greenish fluorescence. 

 Gelatin is feebly liquefied. Found by Rullmann in canal- 

 water (C. B. xxiv, 465). 



