238 BACTERIAL DISEASES OF PLANTS 



or yellow color of the substratum. Both these substrata become 

 alkaline as early as the third day and increasingly so later on; 

 both are softened, especially the carrot which often may be 

 shaken apart in water after a week (Jones) or even in much less 

 time. 



The maximum temperature for growth is between 38° and 

 39°C. The optimum temperature for growth is between 25° 

 and 30°C. The minimum temperature for growth on steamed 

 vegetables is above 4°C. Raw vegetables have not been re- 

 ported upon.^ No appreciable growth was obtained on any 

 medium at 0.6° to 1°C. (20 days) but there was a slight growth 

 on nutrient gelatin at 2° and at 3°C. 



Growth after 5 days at 12°C. on steamed vegetables (potato, 

 carrot, turnip, rutabaga) was about one-third that on the same 

 substrata at 20° to 24°C. 



Except as already noted the cultures were free from strong 

 odors. Not much indol is produced. 



Neutral bouillon gives the best growth, but the organism 

 tolerates sodium hydroxid in bouillon down to below —40 on 

 Fuller's scale and malic acid up to a little beyond -f-30. The 

 organism is sensitive to it own acid products. In peptone 

 water containing grape sugar, swollen, vacuolate and knobby 

 involution-forms occur. 



Tolerates sodium chlorid up to 6+ per cent but not 7 

 per cent in -f-15 peptone beef bouillon. Grows well in -\-15 

 bouillon with 5 per cent NaCl. 



Jones 3a (culture received from him in 1919 — descend- 

 ant of his original isolation of Bacillus carotovorus) tolerates 

 ethyl alcohol up to 7 per cent in -|-15 peptone bouillon: grows 

 promptly and well in the presence of 5 per cent. In further ex- 

 periments it grew readily and formed a heavy pellicle in the 

 presence of 10 per cent ethyl alcohol and made some growth 

 in the presence of 11 per cent, but would not grow in the 

 presence of 12 per cent. See Fig. 184 where the behavior 



1 In October, 1915, growth and rot were obtained by the writer on raw potato 

 and carrot at 5°C. inoculating (3a) from a potato culture, but neither at 5°C. nor 

 at 8°C., inoculating from bouillon. The first rot from the bouillon inoculations 

 was at 9° to ITC. and that feeble (5 days). 



