CERTAIN GENERA OF THE CLOSTRIDIACEAE 5 



I wish most heartily to thank Dr. Karl F. ^leyer for many 

 helpful suggestions which he has given me during the compila- 

 tion of this classification. 



Artificial Key to the Geneha of the Clostridioideae 



A. Do not produce HjS demonstrable by lead-acetate-paper test when grown in 

 blood-broth. 

 B. Do not liquefy gelatin 



C. Very large rods that form oval spores and store up starch in carbo- 

 hydrate media. 



Genus 1. Clostridium. Prazmowski em- 

 mcnd. Heller. Type species bulyricum 

 as described by Winogradsky (1895). 

 CC. Rods with spherical spores. 



D. Do not grow on media containing much protein. 



Genus L'. Omelianskillus nov. gen. Type 

 species hydrogcnicus as described by 

 Omeliansky (1895 and 1904b). 

 DD. Grow on ordinary anaerobe media. 



E. Sides of the bacilli parallel, spores strictly terminal. 



Genus 3. Macinloshillus nov. gen. Type 



species Ictanomorphus (pseudotetanus 



bacillus, Mcintosh ('p.32). Bacillus tetano- 



morphus Committee (p. 41)), as described 



by the Conmiittee. 



EE. Spores not always strictly terminal, sides of 



bacilli may not be parallel. 



Genus 4. Donglasillus nov. gen. Type 

 species sphenoides (Bacillus sphenoides 

 Douglas Fleming and Colebronk), as 

 described by the Committee (p. 43). 

 CCC. Slender rods with oval endspores, usually Gram-negative. 



D. Clot milk and attack various sugars, produce much acid. 

 Genus 5. Henrillus nov. gen. Type spe- 

 cies tertius (Bacillus iertius Henry) as 

 described bj' Henry. 

 DD. Do not clot milk, attack few or no sugars, produce 

 little acid. 



Genus 6. Flemingillus nov. gen. Type 

 species cochlearius (Bacillus cochlearius 

 Douglas Fleming and Colebrook) as de- 

 scribed by the Committee (p. 40). 

 CCCC. Gram-positive rods which are not markedly slender and which 

 produce oval spores. 

 D. Clot milk, saccharolytic. 



E. Sponilate meagerly, attack a few sugars; occasion- 

 ally moderately pathogenic tissue invaders. 



