Studies of Bacillus Radicicola of Canada Field Pea 



71 



Results 



The nature and the composition of the four media used in experiment 

 13 are given in table 1, page 11. No nitrogen in any form was added to 

 medium 335. The other three media received 0.3 per cent of Liebig's 

 beef extract, and, in addition to this, media 300 and 310 received 1 per 

 cent and mecUmn 400 received 2 per cent of Witte's peptone. Medium 

 335 contained 2 per cent of cane sugar, and medium 310 contained 2 per 

 cent of dextrose. 



As seen from table 17, the age of the individual cultures varied between 

 fifteen days and one hundred and fifteen days; but the organisms in all 

 the cultures, except 27, 28, and 29, had been under the mfiuence of their 

 respective media for one hundred and fifteen clays. Cultures 27, 28, and 

 29 were fifteen days old and had been under the mfiuence of their respec- 

 tive media for only fifteen days, havmg been groTvm previously on medium 

 335. 



The influence of these four media on the organism is shown in table 17. 

 In order to bring out the relations more clearly, a part of these data are 

 rearranged m table 18: 



TABLE 18. Influence of Age of Cultures on the Given Media 



Laboratory number of culture 



Culture 

 medium 



Age of 

 culture 



(days) 



Average 



number 



of nodules 



per plant 



Number of 



living 

 organisms 

 in culture 



23 ...... 



335 

 335 

 335 

 335 

 335 

 335 

 335 



300 

 300 

 300 

 300 

 300 

 300 



400 

 400 

 400 

 400 



15 



49 



61 



81 



105 



110 



115 



15 



49 



81 



105 



110 



115 



15 

 49 

 61 



81 



4.5 

 6.2 

 9.8 

 6.9 

 9.5 

 7.3 

 9.8 



8.5 

 11.2 

 

 

 

 



5.8 

 6.8 



7.7 

 8.5 



576,000,000 



19 . . . 



216,000,000 



16 



396,000,000 



12 



180,000,000 



7 



360,000,000 



4 



350,000,000 



1 



300,000,000 



24 



4,320,000,000 



20 



16,000,000 



13 







8 







5 







2 







25 



2,592,000,000 



21 



252,000,000 



17 



10,000,000 



14 



1,000,000 



