Litmus milk: Acid; coagulated; pep- tonized. Potato: Moderate, white to yellow growth. Indole not produced. Does not utilize urea as a source of ni- trogen. Acid from glucose, lactose and sucrose. Some strains form acid from mannitol, others from glycerol. Starch not hydrolyzed. Nitrites not produced from nitrates. Ammonia produced from peptone. Ammonium salts are utilized. Saprophytic. Aerobic. Optimum temperature, 20° C. Habitat: Found in milk and dairy uten- sils. 4. Micrococcus flavus Trevisan, 1889. {Micrococcus flavus liquefaciens Fliigge, Die Mikroorganismen, 2 Aufl., 1886, 174; Trevi- san, I generi e le specie delle Batteriacee, Milan, 1889, 34.) fla'vus. L. adj. flavus yellow. Spheres, 0.8 to 0.9 micron in diameter, oc- curring singly, in clumps and occasionally in fours. Occasionally cultures are found that are motile with a single flagellum, otherwise they are non-motile. Gram-variable. Gelatin colonies: Small, circular, yellow- ish to yellowish brown, somewhat serrate margin, granulated, sharply contoured. Gelatin stab: Yellow, wrinkled surface growth with slow, crateriform liquefaction. Agar colonies: Small, pale yellowish, homogeneous, entire. Agar-slant: Growth canary-yellow, some- what dry, wrinkled, raised, entire. Broth: Turbid with yellowish ring and sediment. Litmus milk: Slightly acid; soft coagulum formed with slight reduction; slowly pep- tonized. Potato: Slight, canary-yellow growth. Indole not produced. Acid is generally formed from glucose and lactose. Sucrose, glycerol and mannitol generally not fermented. Starch not hydrolyzed. Nitrites not produced from nitrates. Generally produces growth on NH4H2PO4 media. Ammonia produced from peptone. Non-pathogenic. Aerobic. Optimum temperature, 25° C. Source: Original source not given. Habitat: Found in skin gland secretions, milk, dairy products and dairy utensils. 5. Micrococcus candidus Cohn, 1872. (Beitrage z. Biol. d. Pflanzen, 1, Heft 2, 1872, 160.) can'di.dus. L. adj. candidus shining white. Spheres 0.5 to 0.7 micron in diameter, occurring singly. Non-motile. Gram-posi- tive. Gelatin colonies: White, granular, with irregular or entire margin. Gelatin stab: White surface growth. Fili- form. No liquefaction. Agar colonies : Punctiform, white, smooth, entire, iridescent. Agar slant: Smooth, white, glistening, iridescent growth. Broth: Turbid with pellicle. Litmus milk: Slightly acid; not coagu- lated. Potato: Thick, porcelain-white, glisten- ing growth. Indole not produced. Acid from glucose, sucrose, lactose and glycerol. Starch not hydrolyzed. Nitrites not produced from nitrates. Ammonia produced from peptone. Ammonium salts not utilized. Non-pathogenic. Aerobic. Optimum temperature, 25° C. Source: Originally appeared as white colonies on cooked potato exposed to dust contaminations. Habitat: Found in skin secretions, milk and dairy products. 6. Micrococcus cryophilus McLean et al., 1951. (McLean, Sulzbacher and Mudd, Jour. Bact., 6B, 1951, 723.) cry.o'phi.lus. Gr. noun cryus cold, frost;
