386 Journal of Agricultural Research voi. xiii, no. 7 



to over 50 on the covered sides. On 25-niinute plates from 3 to 5 colonies 

 appeared on the exposed sides, while more than 50 appeared on the 

 covered sides. Many colonies appeared on the exposed sides of 15 and 

 20 minute plates. 



RELATION TO MOISTURE 



The organism is killed readily by drying. When a +15 bouillon 

 transfer is kept in the refrigerator for one day at 11° to 12° C, there is 

 clouding but no heavy growth. If transfers of drops are made to sterile 

 cover glasses from such a culture and the cover glasses kept in the dark 

 at 25° to 27°, the bacteria die in five hours but are still alive at three 

 hours. The test was made by dropping them in tubes of beef bouillon 

 after those intervals had elapsed. 



If a I -day-old heavily clouded -I-15 bouillon culture, which contains 

 the clumps of bacteria is used, drying does not take place so readily, and 

 cover glasses in the dark at 24° will still have live bacteria on them after 

 drying for six days. 



VITALITY IN CULTURE MEDIA 



The organism lives for 5 months in beef -agar stabs and more than six 

 months in beef bouillon and sterile milk when kept at room temperatures 

 varying from 24° to 30° C. If evaporation is such that the cultures 

 dry down, they will die before this time has elapsed Cultures kept 

 in the refrigerator will live from 9 to 10 months. 



LOSS OF VIRULENCE 



The organism is still virulent at the time of writing, more than 

 a year after isolation. 



GROUP NUMBER 



According to the descriptive chart of the Society of American Bacteri- 

 ologists, the group number is 2 11. 2323 123. 



The name ''Bacterium marginale, n. sp." is suggested. 



BRIEI'' TECHNICAL DESCRIPTION OF THE ORGANISM 



Bacterium marginale, n. sp. 



It is a short rod with rounded ends; flagella i to 3 bipolar, capsules; pseudozoo- 

 gloese; no spores; few involution forms noted; aerobic; agar colonies cream-colored 

 when young, yellow when mature and the agar a brilliant green; clouds bouillon very 

 heavily in 24hom-s at 20° to 30° C, and in six days the medium is apple-green; growth 

 on potato cylinders is scanty and dirty cream-colored (PL E, 5, 6); later it is 

 a warm-buff. The potato darkens slowly; the diastasic action is feeble; liquefies 

 gelatin slowly; produces ammonia; fluorescence green; reduces nitrates; does not 

 produce indol nor hydrogen sulphid; grows in Uschinsky's but not in Cohn's or 

 Fermi's solution; optimum temperature 25° to 26°; maximum 38°; minimum below 

 0°. Thermal death point 52° to 53° (under conditions stated); vitality at room 



