12 E. M. MEYER 



scopically — in twenty-four hours mainly vegetative forms, in 

 forty-eight hours spore-bearing forms and later only free spores. 



Agar stab at 37° C. Growth along entire line of inoculation 

 into depths of agar. Growth somewhat echinulate. In meat 

 infusion agar many gas bubbles, due to fermentation of muscle 

 sugar (inosite). 



Agar plate. Nutrient agar twenty-four hours at 37°C., colo- 

 nies discrete, round, thin and small (1 mm. diameter), edges 

 smooth. 



Endo's plates at 37°C. Twenty-four hours, colonies pink with 

 red center, irregular contour, 1 to 2 mm. diameter, little or no 

 sheen. Colonies forty-eight hours, deep red, much sheen in 

 colonies and surrounding medium. Latter point distinctive. 



Gelatin plate at 20°C. Forty-eight hours, colonies small (0.5 to 

 1 mm. diameter), round, incipient liquefaction. Colonies 

 seventy-two hours — liquefaction, round, edges regular, 2 to 3 

 mm. diameter. • 



Gelatin stab at 20°C. Forty-eight hours, beginning liquefac- 

 tion; in seventy-two hours liquefaction iniundibuliform, slight 

 precipitate. 



Carbohydrates. In standard extract broth to which has been 

 added one percent of the following carbohydrates, acid and gas 

 are formed: (1) Glucose, (2) laevulose, (3) raffinose, (4) mal- 

 tose, (5) sucrose, (6) lactose, (7) inulin, (8) starch, (9) glycerol, 

 (10) mannitol. No acid or gas and little growth in dulcite broth, 

 which remained clear and limpid. In other broths gas usu- 

 ally appeared in twenty-four hours. Media uniformly clouded, 

 sUght stringy precipitate, no pellicle. Media forty-eighty hours, 

 slightly viscous. 



Glucose neuiral-red broth. Same reaction as that of B. coli, 

 i.e., yellow fluorescence with gas formation. 



Clark's glucose, peptone, phosphate, medium (0.5 per cent 

 glucose, 0.5 per cent K2HPO4 and 0.5 per cent peptone broth), 

 typical reaction of ''Grain" type coli, in forty-eight hours at 

 37°C., i.e. reaction alkaline to methyl red, Voges-Proskauer test 

 positive. 



