30 A SOFT KOT OF THE CALLA LILY. 



Several i)icces were iheii out out with a steril(> knife and placed in 

 sterile petri disbe.s, four pieces in each di.sh. Two pieces in each dish 

 were inoculated with a 24-hour-old culture of the calla-rot "-erm in 

 beef broth and two pieces were left for control. After four days a 

 slight growth was noticeable, but the rate of growth was vevy slow. 



Jiaw jjineajjjjlcs. — The outside was removed and several pieces were 

 cut from the interior with a sterile knife. As in the previous case, 

 four pieces were placed in each of several petri dishes. Two pieces in 

 each dish were inoculated as above and two left for control. These 

 preparations were kept for about ten daA's, but no growth appeared on 

 any of the pieces. 



liavj i/t'lio'w hana7ias. — The outside of the bananas was carefully 

 peeled off, and with a sterile knife cross sections from 1./ to 2 cm. thick 

 were cut otl' and placed in sterile petri dishes, four in each dish. As 

 in the preceding cases, two pieces in each were inoculated with a 24- 

 hour-old cultui'c of the calla-rot germ in beef ])roth and two were left 

 for control. After ten da3's no growth was noticeal)le on an}' of the 

 pieces. 



GAS. 



To determine whether or not the calla-rot organism is a gas pro- 

 ducer, six solutions were used, viz, peptene water +1 \)v,\- cent man- 

 nite, peptone water -|-1 per cent maltose, peptone water +1 per cent 

 dextrose, peptone water +1 per cent cane sugar, peptone water +1 

 per cent milk sugar, and peptone water +1 percent gh'cerin. A half 

 dozen fermentation tubes were tilled with each of these solutions, and 

 after sterilizing for fifteen minutes on three consecutive days several 

 tubes of each set were inoculated with a 1-mm. loop of a 24-hour-old 

 beef-broth culture of the calla-rot organism. A part of each set was left 

 for control. In eighteen hours after inoculation of the infected tubes 

 (temperature, 20"^ C.) the}' were clouded in the bulb, and the cloudmg 

 extended from one-half to 1 inch into the closed ends of the tubes. 

 In forty hours the clouding extended to the top of the closed end of 

 each inoculated tube, but no gas had formed in any case. (Fig. 0.) The 

 control tubes were all clear and free from gas. These tubes were kept 

 under observation for two weeks, but no gas formed in any of the 

 tubes, and the control tubes were still clear and free from sediment. 

 The inoculated peptone-mannite tubes l)egan to clear at the top of the 

 closed ends in from twenty to thirty weeks after inoculation. The 

 deposit formed from a settling of the sediment was cream butf in 

 color, as seen by reflected light, and corresponded very nearly to 

 Ridgway's No. 11. Plate V. The reaction of the contents of the tube 

 was slightly acid to litmus at the close of the experiment. The inocu- 

 lated peptone-maltose tubes ])egan to clear in from ten to twelve 

 weeks, and by the end of twenty weeks were entirely clear. The 



