20 A SOFT ROT OF THE CALLA LILY. 



Litmus milh hi nitrogen. — It was noticed that the litiuu.s milk tubes, 

 whether they had ])cen inocuhited or not, contained a deposit of bhie 

 litnuis. The calla organism that bleached the litmus in the milk failed 

 to attack this deposit, so that it remained blue. It was suggested that 

 the milk possibly contained an anaerobic bacterium that was not 

 destroyed by sterilizing and that it favored the formation of the blue 

 deposit. The two control tubes of litmus milk were placed in a bottle 

 holding about a quart. The bottom of the bottle was covered with 

 pyrogallic acid (powder) to a depth of about one-half inch. To this 

 50 c. c. of a 10 per cent solution of caustic potash were added, and 

 the l)ottle was quickl}^ sealed with Darwin's wax. The mixture was 

 shaken for some time to enable it to take up the oxygen without form- 

 ing much carbon monoxid. If the deposit were due to an anaerobic 

 bacterium, it should increase farther up in the tubes. At the expiration 

 of twelve months the jar was opened. A lighted match thrust just 

 below the level of the opening in the jar was immediately extinguished, 

 showing that the jar still contained nitrogen and had not allowed oxy- 

 gen to enter during this time. An examination of the tubes showed 

 that the blue deposit had not changed. This indicated that the deposit 

 was undoubtedl}'^ a mechanical one and was not due to the presence 

 of an oroanism. The inoculated tubes that were left in the ordinarv 

 air gradually regained their blue color after the organism died. The 

 return of the color (first red, then blue) was apparent whether the 

 oroanisms were left to die of their own accord or whether thev were 

 destroyed b}^ heating ; e. g., if an inoculated litmus tube had entirely 

 faded and was then heated for ten minutes at 100- C, the color 

 returned within twenty-four hours. 



U'i<cliinsl:y''s solution.— Severed tnhes of Uschinsky\s solution were 

 inoculated with a 1-mm. loop of a 21:-hour-old beef-broth culture. 

 Seventeen hours later at 2.5*-' C. all inoculated tubes were slightly 

 clouded. Thirty-six hours after inoculation the tubes were decidedly 

 clouded throughout, with a slight whitish deposit in some of them. 

 The cloudiness was not uniform in all parts of the same tube, but was 

 somewhat stratified. Both the cloudiness and the deposit increased 

 from day to day, until at the end of one week the solution was uni- 

 formly clouded, milk-white, with a copious white deposit in the bot- 

 tom of the tul)c. Even at the end of three months at normal room 

 temperatures the organism was still alive, as indicated })y the fact that 

 the tubes were still clouded and a 1-nmi. loop placed in beef-broth 

 caused a distinct clouding in twcnt3^-four hours. At this time the 

 precipitate was 'S mm. deep. Plating and inoculating into callas 

 showed it to be the calla organism. This experiment was repeated 

 several times with identical results both in regard to the clouding of 

 the Uschinsky solution and the longevity of the organism in this 

 medium. 



