SPECIES 295 



method. From his results he concluded that the nodule bacteria 

 were not varieties of the same species, but that distinct species 

 existed. 



Klimmer and Kriiger two years later used serological tests to 

 distinguish species. They used the agglutination method princi- 

 pally and complement binding and precipitation for confirmation and 

 control. Working with organisms from eighteen legume species, 

 they divided the bacteria, according to their methods, into nine 

 species which they asserted differed sharply from one another. 



Simon (1914) tested various cultures upon seedlings of several 

 legume species and compared the results with those obtained by 

 using Zipfel's agglutination method. He found that the results of 

 both methods agree substantially. His grouping of the organisms 

 is in general agreement with that of Klimmer and Kriiger. He 

 concluded, however, that "the root bacteria of legumes are rather 

 to be conceived as more or less constant adaptations of the species 

 Bacillus radicicola." 



Burrill and Hansen (1917), after an extensive study of various 

 legume bacteria both with the pot-culture method and the agar 

 test-tube method of Garman, divided the nodule organisms into the 

 following eleven groups according as they are interchangeable for 

 the purpose of inoculation: 



GROUP I. 



Mammoth red clover, Trifolium pratetise perenne. 



Alsike, or Swedish clover, Trifolium hybridum. 



Crimson clover, Trifolium incarnatum. 



Berseem, or Egyptian clover, Trifolium alexandriamnn. 



White clover, Trifolium repens. 



Zigzag, or cow clover, Trifolium medium. 



GROUP II. 



White sweet clover, Melilotus alba. 



Yellow sweet clover, Melilotus officinalis. 



Wild yellow sweet clover, Melilotus indica. 



Alfalfa, Medicago sativa. 



Alfalfa, Medicago falcata. 



Bur clover, Medicago hispida. 



Black medick, or yellow trefoil, Medicago lupalina. 



Funugreek, Trigonella foenum-graecum. 



GROUP III. 



Cowpea, Vigna sinensis. 

 Partridge pea, Cassica chamaecrista. 

 Peanut, Archis hypogoea. 

 Japan clover, Lespedeza striata. 



