296 J. S. LAWRENCE AND W. W. FORD 



Agar stab. Little growth along line of puncture, luxuriant 

 growth on surface. 



Agar Colonies. Superficial colonies round highly refractive 

 with entire edges, or spreading and amoeboid. Under low power 

 opaque with crenated edges. Deep colonies round and regular. 

 Under low power slightly granular with crenated margins. 



Litmus glucose agar slant. Tliick, abundant, white or cream 

 white to yellow growth spreading along the line of inoculation. 

 Medium first turns acid but as growth becomes older it again 

 becomes deep blue. 



Litmus glucose agar colonies. Superficial colonies round, 

 highly refractive, with entire edges or spreading and amoeboid 

 with densest part of the growth along the advancing edge. 

 Under low power of the microscope edges crenated. Deep 

 colonies round or oval and under low power slightly granular 

 with crenated margins. Medium first acidified and then made 

 alkaline. 



Gelatin stab. Cup-shaped or surface liquefaction and scum 

 production. 



Gelatin colonies. Colonies dense with liquefaction centers 

 and granular ring at the edges of a cup-shaped liquefaction. 



Broth. Turbidity and a rather fragile scum appears late. 

 Medium then clears. 



Peptone. Turbidity with small patches of surface growth. 

 Medium soon clears. 



Potato. Growth abundant, moist, brown with finely wrinkled 

 or lichen-like appearance in the majority of instances. At times 

 the fine wrinkling is lacking and only a thick, moist, brown, 

 mealy growth is produced. 



Litmus milk. Slow peptonization with the production of a 

 lilac color turning to amber. In a few weeks digestion is com- 

 plete and only a white sediment is left behind. No acidification 

 No coagulation. 



Blood serum. Thin, white, dry, at times finely wrinkled growth 

 which later becomes yellowish and moist. Suggestion of lique- 

 faction, but this is never complete. 



Fermentation tubes. Glucose. Turbidity and scum in bulb 

 and turbidity in closed arm. Reaction acid. 



