Feb. 1897.] BOTANICAL SOCIETi" OF EDINBUKGH 3 7 



So far for laboratory experiments with sterilised soil. 

 There has not yet been time to obtain many results from 

 experiments made with pure culture inoculation on a field 

 scale, and yet here, too, there is at least an earnest of 

 success. 



Three plots out in the open, each 120 yards square, 

 were planted with ornithopus. The sowing was in May. 



Plot 1 was inoculated with pure culture of ornithopus bacteiia. 

 ,,2 ,, raw earth from another ornithopus licld. 



,, 3 was left uninoculated. 

 When these plants were revised in August, the non-inoculated plot 



averaged 2 small nodules per root. 

 Those inoculated with raw soil plot averaged 3 medium-sized nodules 



per root. 

 Those inoculated with pure ornithopus culture averaged 9 mostly large 

 nodules per root. 



Many experiments on a field scale have been started on 

 the Continent, and, doubtless, during the year many more 

 will be undertaken in Britain. Certainly a good case has 

 been made out in the experiments in the experimental 

 station at Tharand for the value of soil inoculation, and 

 now field experiments under many conditions must give 

 the final answer as to whether or not this special branch 

 of soil inoculation is likely to prove advantageous. 



As to Methods. — Where a soil is deficient in Bacillus 

 radicicola there are two methods of infection — 



1. The bringing to such a field a quantity of soil from 

 another field in which the species of the plant to be sown 

 has already grown well. This soil is then worked in. 

 Dr. Salfeld, of Hanover, holds the honour of having 

 employed this method on a large scale with gratifying 

 results, getting good leguminous crops where such had 

 refused to grow before. Difficulties in the way of using 

 this method of inoculation on a large scale will occur, 

 e.g. uncertainty, questions of cost and transit, the possible 

 introduction of harmful forms, and so on. 



2. There remains the second method, viz. Nobbe 

 and Hilltner's method of inoculation with pure cultures. 

 Such cultures can be made by oneself if the necessary 

 bacteriological training is possessed, but if not, bottles 

 containing the cultures can be bought from Lucius & 

 Bruning, Hoechst a Main, at 2s. 6d. each. So far, culti- 

 vations of the following plants can be procured : — 



