THE CLASSIFICATION OF BACTERIA 2OI 



f Potato cultures never developing a red pigment. 

 Gelatin liquefied. CLASS XV, p. 266. 

 Gelatin not liquefied. CLASS XVI, p. 282. 

 ft Potato cultures developing a red pigment. CLASS XVII, 

 p. 285. 



b. Rods becoming spindle-shaped at sporulation, Clostridium type. 



CLASS XVIII, p. 287. 



c. Rods swollen at one end at sporulation, Tetanus type. CLASS 



XIX, p. 290. 

 2. Obligate anaerobic. 

 . a. Rods not swollen at sporulation. CLASS XX, p. 292. 



b. Rods becoming laterally swollen or spindle-shaped at sporula- 



tion. CLASS XXI, 295. 



c. Rods swollen at one end at sporulation. CLASS XXII, p. 302. 

 B. Chromogenic; produce pigment on gelatin or agar. CLASS XXIII, 



p. 304. 



CLASS I. WITHOUT ENDOSPORES. AEROBIC AND FACULTATIVE 

 ANAEROBIC. COLONIES ON GELATIN PLATES ROUNDISH, NOT 

 AMEBOID OR PROTEUS-LIKE. GELATIN NOT LIQUEFIED. DE- 

 COLORIZED BY GRAM'S METHOD. 



I. Gas generated in glucose bouillon. 



A. Milk coagulated. B. COLI GROUP. 



1. Indol produced, 



a. Phenol produced. 



i . B. Marsiliensis Kruse. 



b. No phenol produced . 



__2. B. coli (Escherich). 



3. B. Wardii. 



2. No indol produced. 



a, 'Gelatin colonies of a distinctly colon type, indistinguishable 



from those of B. coli. 



4. B. anindolicum Lembke. 



b. Gelatin colonies of a character intermediate between the colon 



and aerogenes types (bacteria intermediate between B. coli and 

 Bact. aerogenes} . 



5. B. enteritidis Gartner. 



6. B. chologenes Kruse. 



7. B. toxigenus. 



