526 C. A. LAUBACH, J. L. RICE AND W. W. FORD 



tures (10 days) they are thicker and shghtly brownish. Reac- 

 tion of medium alkahne. 



Gelatin stab. Fihform growth along Hne of inoculation and 

 gradual liquefaction in the form of a sphere below the surface. 

 Liquefaction is slow, taking place only after 7 to 8 days. Lique- 

 faction gradually reaches the walls of the tube. Growth not 

 arborescent. 



Gelatin colonies. Colonies appear only after 5 to 6 days. 

 They are small fine and surrounded by a hazy zone. Gelatin 

 slowly liquefied. Under low power colonies are round regular 

 finely granular with entire margins or may show irregular out- 

 lying strands. 



Broth. Turbidity within 24 to 48 hours with a faint friable 

 scum appearing in about 10 days. 



Peptone. Turbidity within 24 to 48 hours with faint friable 

 scum in 10 days. 



Potato. Moist yellow growth within 24 hours gradually be- 

 coming heaped up and irregular and assuming a brown or red- 

 dish brown color. 



Litmus milk. No change in reaction except for an occasional 

 partial reduction of the litmus. No peptonization. No coagu- 

 lation. 



Blood serum. Pale yellow growth in "24 hours gradually be- 

 coming thick and moist in old cultures. No liquefaction. 



Fermentation tubes. Glucose: turbidity in bowl, no scum, 

 arm clear. Reaction alkaline. 



Saccharose: reactions the same. 



Lactose : reactions the same. 



Thermal death point. The spores stand boiling 15 minutes but 

 are destroyed by boiling for 30 minutes. They resist 15 minutes' 

 exposure in the Arnold but are destroyed by 30 minutes' exposure. 

 They resist autoclaving at a pressure of 12| pounds but are 

 destroyed by 14 pounds pressure. 



