EXPERIMENT STATION BULLETINS. 641 



3. Litmus Milk : 



(a) Peptonization — Slow. 



(b) Reduction from the bottom upward becoming a tan 



colored liquid. 



(c) Alkaline. 



4. Glycerin Potato : 



(a) Abundant, flat. 



(b) Dull, finely wrinkled. 



(c) Cream colored, becoming 'tan. 



(d) Water in bottom pinkish. 



5. Gelatin Agar Colony: 



(a) Growth — Rapid. 



(b) Flat 



(c) Form — Spreading. 



(d) Semitransparent. 



III. Physical and Biochemical Features: 



1. Fermentation tubes, neutral red broth plus 



(a) Dextrose: 



Gas — Negative. 

 Reaction — Acid. 



(b) Lactose: 



Gas — Negative. 

 . Reaction — Alkaline. 



(c) Saccharose: 



Gas — Negative. 

 Reaction — Acid. 



2. Peas in distilled water:* 



(a) Aerobic tubes: 



Gas. 



Creamy top growth becoming deep red underneath ; 



chromogeuesis more readily produced at 37 degrees 



C. 



(b) Anaerobic tubes : 



Gas. 



Not much visible growth, no color. 



3. Peptone Solution: 



(a) Indol production, slight. 



4. Nitrate Peptone Solution: 



(a) Nitrate reduction. 



(b) Ammonia production. 



5. Starch Peptone Solution, neutral : 



(a) Starch reduction. 



(b) Slight test for sugar. 



(c) Slight acid. 



♦See foot note on page 10. 

 81 



