BIOLOGICAL STUDIES ON INTRACELLULAR BACTERIA. 139 



Spirillum from Parcoblatta virginica. 



Morphology. 1.5 per cent, neutral, nutrient agar, short and 

 long rods. In nutrient bouillon longer rods, some curved, others 

 straight. Average length 1.5-2^. Stains readily. Gram nega- 

 tive. No endospores. Motile. A single flagellum attached to 

 one of the poles. 



Nutrient Agar Stroke. 1.5 per cent, neutral. Growth : abund- 

 ant, filiform, flat, glistening, smooth, opaque, butyrous. Odor 

 absent. Medium greened. 



Nutrient Bouillon. Ring, clouding strong, odor absent, sedi- 

 ment abundant. 



Gelatin Stab. Growth best at top ; line of puncture filiform. 

 Liquefaction begins in two days, crateriform. Color of medium 

 unchanged. 



Litmus Milk. Reaction not changed. Not coagulated. Re- 

 duction complete in eight days. 



Milk. Clearing without coagulation. Medium and consist- 

 ency unchanged. No peptonization. 



Potato. Growth abundant, spreading, flat, glistening, smooth, 

 butyrous. Odor absent. Medium unchanged. 



Nutrient Agar Colonies. 1.5 per cent, neutral. Growth rapid 

 at 35 C. ; round, smooth, slightly convex, edge entire, amorphous. 

 Diameter 11^4 mm. 



Nutrient Gelatin Colonies. Growth rapid, irregular, smooth, 

 crateriform, edge undulate, liquefaction saucer. 



Indol test negative. 



NH S test faintly positive. 



Nitrates not reduced to nitrites. 



Diastase Test. Starch converted to sugar. 



Strong catalase reaction in bouillon culture. 



Faint peroxidase reaction with gum guaiac and H 2 O 2 in sugar 

 bouillon culture. 



FERMENTATION OF CARBOHYDRATES WITH FORMATION OF ACID AND GAS. 



Gas. Acid. 



Dextrose o o 



Levulose o o 



Saccharose o o 



Maltose o o 



Lactose o o 



Mannit . o o 



