No. 6. DEPARTMENT OF AGRICULTURE. 379 



is claimed to possess the power of utilizing atmosplieric nitrogen. 

 It is supposed to be particularly valuable in the growth of the 

 cereals which lack the power of utilizing free nitrogen. 



In the use of alinit, both beneficial and indifferent results have 

 been obtained, but the experience in its use have not been as yet ex- 

 tensive enough to warrant definite conclusions being drawn regard- 

 ing its value; but from a theoretical standpoint there is little to 

 recommend it. 



B. ellenhachiensh is probably identical with J3. inegathermm* 

 which is commonly present in soils, in which case nothing new is 

 added to the soil by its use. Furthermore, of the myriads of bac- 

 teria present in a handful of soil, the addition of a relatively in- 

 finitesimal quantity of alinit would be like a drop of water added 

 to a reservoir, and in the struggle for life between these myriads of 

 soil bacteria there is a question whether one B. ellenhachiensis in a 

 million other forms would be certain of a maintained existence, or at 

 any rate be liable to multiply to a degree in excess of the others, suf- 

 ficient to produce appreciable results. 



If soil bacteria in general, as is probably the case, have any im- 

 portant relation to nitrogen assimilation, more is to be gained in 

 following those methods already set forth, which aim to provide for 

 the best development of soil bacteria in general. 



At best, the gain of nitrogen from the use of artificial cultures, 

 or from the stimulation of the development of any nitrogen assimi- 

 lating bacteria already present, will be far below the demands of 

 agricultural plants, and also inferior to the means which we have in 

 the utilization of leguminous plants in our systems of rotation. 



9. Recent Researches on Nitrogen Assimilating Bacteria of 



Soils (Oligonitrophiles. ) 



In 1901, Beijerinckf made a most important contribution to our 

 knowledge of nitrogen assimilating bacteria of the soil. To this 

 class of organisms he gives the name Oligonitrophiles. 



To the oligonitrophiles belong two classes of organisms (1) the 

 lowest microscopic algae, the Cyanophyceae and (2) the bacteria. 



He showed that by seeding soils to solutions containing tap-water 

 and Ko H Po^ and exposing the cultures to the light, an abundant 

 growth of certain Cyanophycae would result, and that certain of 

 these possessed quite active nitrogen assimilating properties. 



By seeding soils into solutions containing potassium phosphate, 

 carbonate of lime acid some carbohydrate such as dextrose or mannit. 



•Since the above was 'written, Severin has probably shown that B. ellenhachiensis Is a dis- 

 tinct species distinct from B. megatherium. Spc. Ccntralblatt f. Bakteriologrie, 2 te. Abt. VTII. 

 1901. 



tBeijerinck. Centralblatt f. BaktPriologie. 2 t Abt. VII. 1901. 562. 



