FAMILY XIII. BACILLACEAE 635 



Key to the species of genus Clostridium. 



I. Strictly anaerobic* 



A. Cellulose not t3-pically fermented. 



1. Distinctive pigments not characteristically produced, 

 a. Central or eccentric to subterminal spores, 

 b. Ovoid spores. 



c. Rods distinctly swollen at sporulation. 

 d. Motile. 



e. Gelatin and/or glucose-gelatin may or may not be liquefied, 

 f. Gelatin and/or glucose-gelatin not liquefied, 

 g. Glucose fermented. 



h. Coagulated albumin not liquefied, 

 i. Milk coagulated. 



j. Stormy fermentation or at least active co- 

 agulation of milk, 

 k. Glycerol may or may not be fer- 

 mented. 



1. Glycerol not fermented. Manuitol 



fermented. 



m. Starch, lactose and sucrose 



fermented. 



n. Starches of potato and of 



maize mash are fermented. 



1. Clostridium butyricum. 



nn. Starch of potato mash 

 but not of maize mash is 

 fermented. 



2. Clostridium butylicum. 



mm. Starch not fermented. Lac- 

 tose and sucrose fermented. 



3. Clostridium beijerinckii. 



11. Glycerol fermented. 



m. Hemolytic on blood agar. 



4. Clostridium multifermentans . 



mm. Non-hemolytic on blood agar. 



5. Clostridium iodophilum. 



kk. Action on glycerol not recorded. Col- 

 onies rubbery mucoid. 



6. Clostridium gumviosum. 



jj. Milk slowly coagulated, not stormily. 

 Glycerol and mannitol not fermented. 



7. Clostridium fallax. 

 ii. Milk not coagulated. 



j. Salicin fermented. 



8. Clostridium difficile. 



jj. Salicin not fermented. 



k. Calcium lactate fermented. 



* Those unfamiliar with anaerobic techniques should consult L. Ds. Smith, Introduction 

 to the Pathogenic Anaerobes, University of Chicago Press, 1955, 253 pp. 



