and Laboratory Methods. 2037 



not reaching to the bottom. Liquefaction infundibuliform and 

 very slow and dry, with a reddish deposit on sides. After 6 to 8 

 weeks the Hquefaction becomes horizontal, more liquid accumulates, 

 and a red deposit is formed. 

 Plate culture — Surface col.; growth slow. After two days a small, 

 round, white colony, which after 4 to 5 days develops into a colony 

 about 2 mm. in diameter, round and smooth. Under the micro- 

 scope it appears granular with a large opaque center surrounded 

 by a more transparent ring, while the outside ring is transparent. 

 Agar: Streak culture — Abundant, moist, smooth, opaque salmon-colored 

 growth in 24 hours at 37°. With age, it becomes slightly ferruginous 

 in color. 

 Milk: After three days, at 37°, there is a reddish-colored ring at the top. 

 In five days a soft curd is formed of amphoteric reaction. Subsequent 

 digestion is slow, and not complete for 4 or 5 weeks. Litmus milk 

 decolorized. 

 Potato : Abundant spreading, reddish to ferruginous-colored, moist growth. 

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

 Synthetic Media : No reduction of nitrates. 

 Bouillon : Growth slow at all temperatures. After three days the liquid 



becomes turbid, and a white sediment is deposited. 

 This bacterium was found almost constantly present in the milk of one of 

 the cows tested,- but was never found in that of any other. There were never 

 more than one to four colonies per plate present, so that its eflFect on the milk 

 was very inconsiderable. Its similarity to Bad. exiguuni of Wright (19) is most 

 marked. Wright isolated this bacterium from water ; but the fact that he found 

 its optimum temperature to be 36° and that it is a facultative anaerobe, does not 

 make it at all surprising that it should be found in the udder of a cow. 



X. Micrococcus No. X. 



Occurrence : Found occasionally in the milk examined. 



General Characters : Shape and arrangement — Micrococcus clustering in 

 twos and fours. 

 Size — of medium size. 

 Motility — None. 

 Spore formation — None. 



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

 Relation to air — Aerobic and facultative anaerobic. 

 Relation to gelatin — Slow liquefaction. 

 Color— White. 



Stain — Stains evenly with ordinary aniline dyes. 



Gelatin : Stick culture — Slight beaded growth about half way to the bottom. 



Liquefaction very slight, crateriform ; thick, white, beaded deposit 



on surface. 



Plate culture — Surface col. ; a granular colony with more liquid 



outer zone. Soon the granular center becomes broken, and the 



