242 The Celery-Rot Bacillus 



is evident that at 25° C. the organism is killed as soon as all visible 

 trace of moisture has disappeared. 



Jones (15) working with B. carotovorus found that in some cases 

 several hours of desiccation were necessary to kill the organism even 

 at a temperature of 28° — 31° C. He used broth cultures and suggested 

 that a surface film was formed which offered protection to the bacilli. 

 On diluting the broth the organism proved much less resistant, two 

 minutes' drying at a temperature of 22° C. sterilizing the cover-glasses. 

 The latter result conforms more closely with the experiments recorded 

 above and it is evident that celery extract on drying does not yield 

 an effective protecting film. 



Summary. 



1. A bacillus isolated from celery affected by soft-rot reproduced 

 the disease when inoculated into celery plants. 



2. Other vegetables commonly grown as garden crops are suscep- 

 tible to attack by the same organism. 



3. The bacillus is very sensitive to the action of antiseptic and 

 germicidal reagents. 



4. It is typically bacilliform but under certain conditions may be 

 almost isodiametric and coccus-like, or it may develop into very long 

 filaments. 



5. It is capable of growing in a synthetic medium containing a 

 sugar or pectin as the sole carbon compound. 



6. Its group number is 221-1113522 and since B. carotovorus 

 Jones proves to be a yellow organism the latter must also be included 

 under that number. The two organisms appear to differ slightly on 

 minor points, e.g. vigour of growth in Uschinsky's solution and on 

 celery extract agar. 



7. Like B. carotovorus the celery-rot organism is very sensitive 

 to desiccation. 



