and Laboratory Methods. 2033 



IV. B. halofaciens (n, sp.). 



Occurrence : Of frequent occurrence in fore and after milk. 

 General Characters : Shape and arrangement — Bacterium occurring singly. 

 Size — Short, about Xy^ 'yi\. 

 Motility — Motile. 

 Spore formation — None. 



Relation to temperature — Grows atroom temp., but optimum temp, is 37°. 

 Relation to air — Aerobic and facultative anaerobic. 

 Relation to gelatin — Slow liquefiier. 

 Color — White, dirty brown, and finally yellow. 

 Stain — Stains evenly with anilin dyes. 

 Gelatin: Stick culture — Beaded growth to bottom of tube, with an abundan' 

 surface growth, at first white but afterwards becoming yellow. At 

 first there is a slight crateriform liquefaction with yellowish deposit 

 and a white halo around edges. After 12 days liquefaction becomes 

 complete. 

 Plate culture — Surface col.; colony is at first white, but soon be- 

 comes brownish, and in about three days intensely lemon-yellow, 

 and the colony, which is about 5 mm. in diameter, becomes sur- 

 rounded with a whitish halo extending out into the gelatin. 

 Agar : Streak culture — A thin, waxy, transparent yellow growth. 

 Milk: A weak alkaline curd is formed in four days, with yellowish ring on 

 top. Subsequent digestion is slow but complete in about three weeks 

 at 37° C. 

 Potato : A moderately thick lemon-yellow growth, somewhat spreading. 

 Smith lube : No gas produced in either glucose or lactose. 

 Synthetic Media : No reduction of nitrates. 

 Bouillon: Becomes cloudy in one day at 37°, and a heavy yellowish deposit 



collects. 

 This bacterium approaches in characteristics Bad. annulatuni, Wright (19), 

 but differs from it in several details, so that we do not hesitate to call it a new 

 species. The name refers to the characteristic halo found in gelatin cultures. 

 As this bacterium was of quite frequent occurrence, we made butter from cream 

 ripened with a culture of it, and found that the flavor of the butter, while not 

 strong, was quite disagreeable. At the same time, its presence in relatively 

 small numbers as compared with Nos. I and II, and the fact that the flavor was 

 not by any means strongly marked, makes this an inconsiderable item so far as 

 the " natural ripening " of such milk is concerned. 



V. Micrococcus varians lactis. Conn, 113 and 104. (21.) 

 Occurrence : Quite frequent in both fore and after milk. 



General Characters : Shape and arrangement — Micrococcus occurring singly. 

 Size — Rather large ; 1 // in diameter. 

 Motility — None. 

 Spore formation — None. 

 Relation to temperature — Grows readily at 18°, but best at 37°. 



