BY R. GtlElG-SMITH. 



149 



Experiment viii. Hay-infusion, 0-1%, with dextrose 0-1%. 

 Soil-bacteria, 12 days at 16"; test-bacteria, 2 days at 22". 

 Inhibiting moderately — Penic. dadosporioides. 

 Inhibiting sHghtly— Actino. 11, Bac. A8, Bac.T.P..^, T.P.I, T.F.5, 



T.P.6, T.P.7,S.B.2, S.B.5. 

 Indifferent— Actino. 10, Bac. S.B.I, S.B.I. 



The results of the experiments, as a whole, showed that the 

 action of the soil-microbe is generally irregular. This is notably 

 the case with Bac. A 17, which is the same as Bac. Al. In some 

 cases, it increased the growth of the test-organism, while, in 

 others, it had an indifferent action. In the case of Rhizobium 

 and of Bac. AT, we have bacteria which produce a luxuriant slime 

 in media containing sugar, and even in those containing merely 

 a trace of sugar or none at all, the inhibiting property is seen to 

 remain. I cannot but think that they acted by extracting the 

 nutrient from within the capsule in order to produce their slime, 

 which remained in the outer tube. The inhibition is, therefore, 

 in all probability, due to the absence of nutrients rather than to 

 tlie presence of toxins in the collodion-capsule. As the experi- 

 ments did not promise to aid the investigation, they were dis- 

 continued. 



The Use of vakious Media. 



The action of Bhizobium led to its being tested in Hasks of 

 various media, and the tests are grouped together in the follow- 

 ing Table. 



