280 FERMENTATIONS IN MILK 



the medium soon becoming liquefied : on potato they are pale 

 yellow. 



(c) Bacterium lactis viscosum, Adametz, is a non-motile, 

 coccus-like bacterium, with a well-developed capsule, about i /a 

 in diameter, and producing slimy whitish colonies on gelatine 

 and agar somewhat like those of Bact. lactis aerogenes. It some- 

 times occurs in threads 2 to 5 p long. When introduced into 

 milk it renders it slightly alkaline and viscous in a day or two, 

 but the stringy condition does not develop until a much longer 

 time has elapsed. The milk sugar is not much altered, the slimy 

 substance being apparently produced at the expense of the casein 

 of the milk. Cream inoculated with it becomes slimy if kept some 

 time, and butter made from such cream is soft and does not keep 

 well. The bacterium is generally introduced to the dairy in the 

 water supply, and is one of the commonest causes of ropy milk. 



Resembling this species is Bs. lactis pituitosi^ Loffler, a thick 

 bacillus which breaks into coccus-like segments and renders milk 

 slightly acid. 



(d) Bacterium Guillebeau, c, Freudenreich, is a type of 

 bacterium isolated from milk yielded by cows suffering from 

 inflammation of the udder. Milk is rendered slimy by it. It 

 produces colonies on gelatine like those of Bact. lactis aerogenes. 



(e) Bacterium Hessii, Guillebeau, a motile form 3 to 5 /& 

 long, i to 2 ft thick, nearly related to the hay bacillus (Bs. sub- 

 tilis}) makes milk ropy, but the ropiness gradually disappears 

 when acidity develops. 



(/) Bs. viscosus, I. van Laer, a bacillus 1.6 to 2.4 /a, 

 long, .8 ft thick, isolated from beer, in which it produces 

 slimy material, can produce ropiness in milk. It forms small 

 white colonies on gelatine plates, which at first are round, 

 becoming slimy with irregular margins later. 



(g) Streptococcus hornensis, Boek., a coccus isolated from 

 slimy milk in Holland, and found in separator slime, water, and 

 on flowers. It produces small white colonies on gelatine. 

 Introduced into milk containing cane sugar at 22 to 30 C., 



