302 .1 Bart I' r ltd Disease 0/ Turnip (Brassica Napns) 



Characters of the Organism. 



Habit. Causes a whitish-grey rot in turnip. 



Morphology. Bacteria l-3ju, to 3fi x -lofi to •9/x with a single 

 polar flagellum. On sugar-rich media it forms long, unequally seg- 

 mented filaments. 



Relation to Oxygen. Evidence for aerobism: Large surface colonies 

 and rapid growth on the surface of the media, buried colonies small; 

 gelatine stab funnel-shaped: rapid decay of turnip in the cotton-plugged 

 flasks and tubes. Evidence for anaerobism: Slight growth on recently 

 steamed agar-slopo tubes cultivated by Buchner'.s method for anaerobes; 

 general turbidity in liquid media enclo.sed in Durham and Fermentation 

 tubes; growth in gelatine stab after sealing mouth of track; decay of 

 turnip blocks in a sealed flask. 



Growth on Gelatine Media. Surface colonies large, round, whitish- 

 grey, margin fibrillated. Liquefies gelktin; stab-culture funnel-shaped 

 in 24 hours, spreading to wall of tube in 48 hours, liquefaction nearly 

 complete. Li the sealed track liquefaction not complete. Colonies on 

 litmus-lactose and litmus-glucose-gelatine produce faint pink margin; 

 on chalk-lacto.se and chalk-glucose-gelatine, hyaline ring; ])oor growth 

 on acidified medium. 



Growth on Agar Media. Surface colonics round or sliglitly lobed, 

 opalescent; sometimes spreading, filmy areas formed; deep colonies oval 

 or spindle-shaped. Growth on agar-streak spreading and filmy. Good 

 growth along agar-stab, spreading at surface. Colonies on litmus-lactose 

 and litmus-glucose-agar produced jiink rnnigiii; or clialk-lacto.se and 

 chalk-glucose-agar hyaline border. 



Growth i.v Bouillon. Rendeivs bouillon turbid, forming a heavy 

 sediment; no pellicle; maximum turbidity in neutral and feebly alkahne 

 broth; neutral reaction to litmus; with 2 per cent, glucose, lactose, and 

 cane-sugar turbidity in open and closed ends of Durham and Fermenta- 

 tion tubes, producing acid reaction without evolution of gas. In Pasteur's 

 solution with cane-sugar turbiditv only in open end of tubes. 



Growth in Nitrate Solution. In Giltay and Aberson's culture 

 fluid strong nitrite reaction after 24 hours with iodine-sulphuric-starch 

 test, with formation of ammonia (Nessler's Test). Heavy sediment formed 

 and film on surface of culture. Control tubes gave neither reaction. 



Growth in Nitrogen- Free Solution. No turbidity; after seven 

 days, petri-cultures in gelatine inoculated from it produced very few 

 colonies. Growth therefore feeble. 



