88 BACTERIOLOGY 



37. M. aquatilis Vaughan 



M. aquatilis-invisibilis Vaughan : Am. Jour. Med. Sci., 1892. 



Morphology. Cocci oval. 



Gelatin colonies. Spreading irregularly ; microscopically deep brown. 



Gelatin stab. Only a slight growth in depth ; on surface growth spreading. 



Agar slant. Growth thin, white. 



Potato. Growth invisible. 



Pathogenesis . Negative. 



Habitat. Water. 



38. M. tenacatis 



M. No. 43 Conn : Conn. (Storrs) Ag. Expt. Sta. Report, 1894, 78. 



Morphology. Cocci oval, 0.7-0.9 ju,. 



Gelatin colonies. Round, smooth, white ; slightly raised. 



Gelatin stab. In depth a good beaded growth ; on surface colony raised, 



transparent, becoming thick, white. 



Agar slant. Growth thin, transparent, tenacious, yellow. 

 Potato. No visible growth. 

 Milk. Unchanged, becoming slightly acid. 

 Bouillon. Turbid ; dense yellowish sediment, becoming clear. 

 Habitat. Milk. 



39. M. acidi-lactici (Lindner) 



Pediococcus acidi-lactici Lindner: Centralblatt f. Bakteriologie, II, 1887, 342. 



Morphology. Cocci 0.6-1.0, solitary, pairs, and tetrads. Optimum temper-'j 

 ature 41 C. 



Gelatin colonies. Small, colorless, becoming yellowish brown. 



Agar stab. On surface growth thin, colorless, moist, glistening. 



Potato. Growth scanty, scarcely visible. Lactic acid is produced in saccha- 

 rine media. 



Habitat. In mash from malt, and in hay infusions. 



40. M. cerevisiae (Balcke) 



Pasteur: Etudes sur la biere, 1876 ; no name. 



Pediococcus cerevisice Balcke : Wochenschrift f. Brauerei, 1884, 183. 



Morphology. Cocci, single, in twos and as tetrads ; involution forms. 

 Gelatin colonies. Small, colorless, becoming yellowish brown. 

 Gelatin stab. In depth a grayish stripe; on the surface growth white, leafy, 

 spreading. 



