THE FAMILIES AND GENERA OF THE BACTERIA 213 



Genus 2. Clostridium Prazmowski 1880, p. 23 



Synonyms: Amylobacter Trecul 1865; Cornilia Trevisan 1889 in part; 

 Granulobacter Beijerinck 1893; Clostrillum Fischer 1895; Clostrinium 

 Fischer 1895; Paracloster Fischer 1895; Semiclostridium Maassen 1905 

 Botulobacillus Jensen 1909; Butyribacillus Jensen 1909; Cellulobacillus 

 Jensen 1909; Putribacillus Jensen 1909. 



Anaerobes or micro-aerophiles. Often parasitic. Rods fre- 

 quently enlarged at sporulation, producing Clostridium or plec- 

 tridium forms. 



The type species is Clostridium butyricum Prazmowski. 



IV. ARTIFICIAL KEY TO THE FAMILIES AND GENERA OF 

 THE ACTINOMYCETALES AND EUBACTERIALES 



A. Typically filamentous forms. Actinomycetaceae 



B. Mycelium and conidia formed Actinomyces 



BB. No true mycelium 

 C. Cells show branching 



D. Gram negative Actinobacillus 



DD. Gram positive Erysipelothrix 



CC. Cells never branch. Gram positive threads later fragmenting 



into rods Leptotrichia 



AA. Typically unicellular forms (although chains of cells may occur) 

 B. Spherical cells. Coccaceae 

 C. Parasitic forms. Cells in pairs, chains or irregular groups, never 

 in packets. Generally active fermenters 

 D. Cells in flattened coffee-bean- like pairs 



Gram negative Neisseria. 



DD. Cells not as above. Gram positive 

 E. Cells in lanceolate pairs or chains 

 Growth on media not abundant 

 F. Cells in lanceolate pairs. Inulin generally fermented . . Diplococcus 



FF. Cells in chains. Inulin generally not fermented Streptococcus 



EE. Cells in irregular groups. Growth on media fairly vigorous. 



White or orange pigment Staphylococcus 



CC. Saprophytic forms. Chains occurring in zoogleal masses in 



sugar solutions Leuconostoc 



CCC. Saprophytic forms. Cells in irregular groups or packets, not in 

 chains. Fermentative powers low 



D. Packets formed Sarcina 



DD. No packets 



E. Yellow pigment Micrococcus 



EE. Red pigment Rhodococcus 



