tract; will grow in selected synthetic media using pneumococcal capsular poly- saccharide as the sole source of carbon Saccharobacterium Note: This genus is recorded in the sixth but not in the seventh edition of the Manual. Not as above 10 10. Colonies with a purple pigment Chromobacterium p. 292 Note: Chromobacterium marismortui has a bluish-brown pigment; see also Pseiidomonas iodinum and Pseudomonas beijerinckii. Colonies red at 37° or 25°C., sometimes with a red, soluble pigment 11 Other than above 17 11. Red color due to prodigiosin; motile by means of peritrichous flagella or non-motile Serratia p. 359 Red color not due to prodigiosin 12 12. Obligate halophiles requiring 20 to 30 per cent salt for growth; highly pleomorphic Halobacterium p. 207 Not obligately halophilic 13 13. Organisms metabolize alkylamines; non-motile or motile by means of polar flagella Protaniinobacter p. 200 Not as above 14 14. Motile by means of polar flagella; straight or curved rods 15 Motile by means of peritrichous flagella 16 15. Straight rods Pseudomonas p. 89 (P. melophthora) Curved rods Vibrio p. 229 (F. extorquens and V. hyphalus) 16. Methyl-red positive; Voges-Proskauer negative Escherichia p. 335 (E. aurescens) Methyl-red negative; Voges-Proskauer positive; pathogenic on rhubarb Erwinia p. 349 {E. rhapontica) 17. Organisms produce a water-soluble, blue, green or yellow pigment 18 Not as above 19 18. Agar hydrolyzed; alginic acid decomposed Alginomonas p. 202 (A. fucicola) (See also Pseudomonas gelatica and Vibrio Juscus.) Agar not hydrolyzed Pseudomonas p. 89 19. Plant pathogens 20 Not pathogenic or known to be pathogenic to plants 24 20. Organisms produce hyperplastic diseases such as galls and hairy root Agrobacterium p. 288 Not as above 21 21. Colonies yellow 22 Colonies not yellow 23 22. Flagella polar Xanthomonas p. 152 (See also Bacterium tardicrescens, Bacterium albilineans, Pseudomonas trifolii, Pseudomonas panicimiliacei , Pseudomonas radiciperda and Pseudomonas levistici.) Flagella peritrichous Erwinia p. 349 Note: The following j'ellow-pigmented pathogenic organisms are either non- motile or motility has not been recorded: Bacterium stewartii, Xanthomonas clerodendri, Xanthomonas sesbaniae and Corijnebacterium agropyri. 23. Flagella polar Pseudomonas p. 89 (See also Xanthomonas panici, X. proteamaculans, X. manihotis, X. rubrisubalbi- cans, X. cannae, X. zingiberi and X. translucens.) Flagella peritrichous Erwinia p. 349
