Nitrogen Fixation by Yeasts and Other Fungi

Since the epoch making discoveries of Hellriegel~ there have followed in quick succession many series of investigations relative to the hxation of atmospheric nitrogen by living organisms. Especially brilliant are the investigations of Winogradskyt on Clostridium pastorianum and those of Beyerincka on the Azotobacter group, and it is unnecessary here to go into a review of the investigations which have since added themselves to those, for the reader is doubtless acquainted with the painstaking and interesting researches of Gerlach and Vogel, Kriiger and Schneidewind, J. G. Lipman, Liihnis, Christensen and a host of others to whom we are indebted for information on the subject of the fixation of atmospheric nitrogen by soil bacteria. Suffice it to say, that the researches of the past twenty-five years have disclosed facts which point emphatically toward the conclusion that the earth is endowed with agencies which, at least in part, compensate for the losses from our valuable nitrogen store from the soil which are constantly going on. From the earliest of these researches it appeared that the power of living organisms to assimilate atmospheric nitrogen was limited to a small group of bacteria of which the power seemed as characteristic and distinct as did the power of the group of nitrifying bacteria to change ammonium compounds to nitrates, but the later investigations soon brought to light the fact that many bacteria other than those of the B. radicicola, the Azotobacter and the Clostridium groups exhibited the power, more or less pronounced, of king atmospheric nitro-