34 Annals Entomological Society of America [Vol. XI, 



Nitrate solution. Nitrates reduced to nitrites. 



Indol production. Absent. 



Hydrogen sulphide production. Absent. 



Fermentation of carbohydrates with gas. 



Dextrose + Lactose + 



Levulose + Mannit + 



Saccharose O Adonit + 



Maltose + Dulcit O 



Pathogenicity. Pathogenic to Melanoplus femur-rubrum, Encopto- 

 lophus sordidus, and Gryllus pennsylvanicus . Pathogenicity not tested 

 out on any other forms. 



Culture sent by d'Herelle under the name Coccohacillus 

 acridiorum. Culture labeled "Souche Cham": 



Morphology. From 1^% nutrient agar stroke 48 hours old, small 

 diplococci. All very uniform. No bacilli. In water of condensation 

 all transition forms between diplococci and bacilli. Highly polymor- 

 phous.* From milk 48 hours old, small diplococci, no bacilH. From 

 bouillon 48 hours old, all intermediate stages between true bacilli 

 and coccus fornis. Nutrient bouillon is a favorable medium for the 

 development of the bacillus forms. SoHd media Hke nutrient and potato 

 agar are favorable for the development of the diplococcus forms. 

 This can be easily demonstrated by transferring from the liquid to the 

 solid medium and vice versa. Diameter of cocci .6m. Length of 

 bacilli .7-1. 5m. Motile. Gram negative. Stains readily. 



Nutrient agar stroke. 13^%. Neutral. Grow1:h abundant, spread- 

 ing, flat, glistening, smooth, opaque, odor absent, butyrous, color of 

 medium unchanged. 



Potato agar stroke. 13^%. Neutral. Growth very luxuriant, 

 spreading, flat, glistening, smooth, opaque, odor absent, butyrous, color 

 of medium unchanged. 



Potato. Growth abundant, whitish. 



Gelatin stab. GroA\i:h uniform, beaded, gas, liquifaction, "medium 

 unchanged. 



Nutrient broth. Ring, slight pellicle, clouding strong, sediment 

 abundant, odor absent, no clearing after fifteen days. 



Milk. Weak acidity, no coagulation, color of medium unchanged. 



Litmus milk. Weak acidity, no coagulation, no reduction. 



Gelatin colonies. Growth rapid, round, convex, edge entire, gas, 

 diameter of colony .5-1 mm. 



Nutrient agar colonies. Growth rapid, round, smooth, flat, edge 

 entire, amorphous, diameter of colony 2.5-3 mm. 



Ammonia production. Positive. 



Nitrate solution. Nitrates reduced to nitrites. 



Indol production. Negative. 



*For an interesting article on pleomorphism see: Studies in pleomorphismin 

 Typhus and other diseases by Edward C. Hor.t. Abstract in Jour. Royal Micros. 

 Soc, December, 1916. 



