

MARYLAND AGRICULTURAL EXPERIMENT STATION. 



Because of the fact frequently observed that one kind of legume 

 would not produce nodules in soil which abundantly supplied another 

 legume with these growths, it has been supposed that each legume re- 

 quired a special and peculiar nodule organism. 



Efforts have been made to distinguish between these bacteria 

 specifically, and separate names have been assigned to the microbes 

 from nodules of peas, beans, clover, etc. Most investigators, however, 



Fig. 2 — Peanut — After Abel, Farmers' Bulletin 121, United States Department of 



Agriculture. 



have been unable to discover any constant difference in the appearance 

 and general characteristics of the bacteria of the various legume 

 nodules, and the results of the most recent research on this question 

 seem to prove that there is only a difference in variety and not in 

 species. 



Dr. Geo. T. Moore, of the United States Department of Agri- 

 culture, Washington, D. C, in laboratory experiments, succeeded in 

 producing nodules on a large number of legumes by inoculation with a 

 single culture. As a result of a great many cross-inoculations, made in 

 every possible combination, Dr. Moore concludes, "that it was satis- 

 factorily demonstrated that it is possible to cause the formation of 

 nodules upon practically all legumes no matter what the source of the 

 original organisms." Nevertheless, it is certainly true that the bacteria 

 seem to adapt themselves to the conditions surrounding the growth of 

 a particular legume and, from a practical standpoint, it will be nec- 

 essary, in order to obtain the best results, to use specific cultures or 

 sources of bacteria for specific crops. 



