IIO DETERMINATION OF SPECIES. 
A. Liquefy gelatin slowly. 
UROBACILLUS GROUP OF MIQUEL, 
B. Liquefy gelatin quickly. 
(a) Potato cultures rugose. 
POTATO-BACILLUS GROUP. 
B. mesentericus type. 
(4) Potato cultures smooth. 
B. SUBTILIS GROUP. 
B. subtilis type. 
2. Obligate anaérobic. 
A. Rods not swollen at sporulation. 
MALIGNANT EDEMA GROUP. 
B. chatveei type. 
B. Rods clavate at sporulation. 
TETANUS GROUP. 
B. tetani type. 
II. Spore formation not observed. 
1. Aérobic and facultative anaérobic. 
A. Gelatin colonies roundish, not distinctly 
ameboid. 
(a) Do not liquefy gelatin. 
1. Do not stain by Gram’s method. 
a. Generate gas in glucose bouillon. 
(1) Coagulate milk. 
CoLON GROUP. 
B. coli type. 
(2) Do not coagulate milk. 
HOG-CHOLERA GROUP. 
B. suipestifer type. 
