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liquefactioo. Agar colonies, not characteristic in ten days, small, 

 white, with fragmented edges. An agar slant culture shows a 

 white, smooth, shining, somewhat luxuriant growth. In old cul- 

 tures the medium takes on a distinct wine-red color, clear and 

 transparent. Zimmermann does not specify this as true for 

 agar, only for gelatin and potato. A heavy cream white layer 

 forms on potato, which later becomes yellow brown. I observed 

 no rose color here, but a brown discoloration of the potato. 

 Bouillon becomes cloudy with a white surface pellicle; after 

 6 8 weeks it may show a slight reddish tinge. Litmus milk is 

 decolorized and acid, but coagulates at the end of ten days only 

 on boiling. No gas is formed, no growth at 37 C, nitrate reduced 

 to nitrite, facultative anaerobe. 



B. lactorubefaciens (Gruber) (68). 



Received from Gruber in November, 1902. Upon examination 

 it agreed closely with the original description. I found however, 

 that the deep growth in gelatin was sometimes arborescent, and 

 that the medium was tinged red. On agar and potato, a white 

 spreading growth. Bouillon is turbid, with pellicle and sediment. 

 The colonies are coli-like. Milk is made rose colored and very 

 slimy; litmus milk shows slight acidity, but does not coagulate at 

 room temperature. The organism does not develop at 37 C, which 

 fact, together with its behavior in milk, its lack of yellow pigment, 

 and its motility, distinguish it from B. lactis erythrogenes. 



B. rutilescens (n. sp.). 



Isolated from Mississippi River water in 1901. Its characters 

 connect it both with the Prodigiosus group and with the Lac- 

 tis erythrogenes group. Morphologically, an actively motile 

 bacillus, like B. rutilus and B. r ubefaciens, unlike B. lactis 

 erythrogenes. No spores. Gelatin plates show white, non 

 characteristic colonies which soon liquefy the gelatin. A stab cul- 

 ture is liquefied rapidly, with a white cumulus sediment, and a 

 white pellicle. Later the liquid portion becomes a beautiful clear 

 rose, and the floating pieces of sediment take on a pink tinge. 

 Agar colonies are often spreading, like those of B. rutilus or 

 B. ruber indicus, without pigment. Agar slant shows a luxu- 

 riant, smooth, moist, white growth, much like the pigmentless 

 culture of B. fuchsinus. Potato, luxuriant, white, and spreading. 

 Bouillon, marked turbidity, with white sediment and thin pellicle. 

 Litmus milk, at room temperature slightly acid, coagulating in 

 three days. At 37 C, coagulation in 48 hours, followed by partial 

 peptonization. Gas production, negative; facultative anaerobe, ni- 

 trates reduced to nitrites. Unlike B. rubefaciens, grows rapidly 

 at 37 C. 



B. mycoides roseus (Scholl). 

 What seems to be the original description of this organism is 



