2 5 6 



BACTERIA IN RELATION TO PLANT DISEASES. 



TABLE 35. Result of Inoculating B. solanacearum into 20 Types of Nicotiana rustica. 



"The possibility remains that Uyeda possessed another truly immune variety, yet his communi- 

 cations on other infection experiments which have been described earlier, make this highly improbable. ' ' 



(9) ON THE VARIABILITY OF BACILLUS SOLANACEARUM SMITH. 



During the search for combinations of carbon and nitrogen foods by means of which the slime- 

 bacteria could be easily recognized, a variable behavior was often observed in media inoculated from 

 the same culture. 



That this did not depend on faults of technic is shown by the fact that transfers of the bacteria 

 into far more than 200 cultures of bouillon always succeeded ; also all grew when inoculated into pep- 

 tone-water (33 cultures), solution of ammonium succinate (32 cultures), ammonium lactate (33 cul- 

 tures), asparagin with sodium malate (21 cultures), and sodium succinate (21 cultures). 



In the test-tubes in which visible growth occurred the originally feebly acid reaction of the solu- 

 tion had become neutral, or alkaline (if growth was strong), while the tubes that remained clear 

 always retained the feebly acid reaction to litmus. 



Experiments were then made by inoculating into solutions whose acidity or alkalinity had been 

 increased slightly, with the results given in table 36. 



TABLE 36. Growth of B. solanacearum in Meyer's Mineral Solution with 0.2 per cent Glycocoll and 

 Glucose or Mannil with Variable Reactions (Cultures always in Sets of 3). 



