98 GENERAL SYSTEMATIC BACTERIOLOGY 



BB. No true mycelium. 



C. Cells show branching. 



D. Gram-negative Actinobacillus 



DD. Gram-positive Erysipelothrix 



CO. 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 fer- 

 mented Diplococcus 



FF. Cells in chains. Inulin generally not fermented. 

 Streptococcus 

 EE. Cells in irregular groups. Growth on media fairly 

 vigorous. 

 White or orange Tpigment . Staphylococcus 

 CC. Saprophytic forms. Chains occurring in zoogleal masses in sugar 



solutions Leuconostoc 



CCC. Saprophjrtic 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 



BB. Rods. 



C. Curved rods. Spirillaceae. 



D. Short comma-like rods. One to three short flagella. 



Vibrio 

 DD. Long spirals, five to twenty flagella. 



Spirillum 

 CC. Straight rods. 



D. No endospores. 



E. Rods of irregular shape or showing branched or filamen- 

 tous involution forms. 



F. Animal parasites. Cells of irregular shape. 

 Staining unevenly. 



G. Acid fast Mycobacterium 



GG. Not acid fast. 



H. Cells elongate, fusiform. 

 Fusiformis 

 HH. Cells not fusiform, sometimes branching. 



