FROM THE AIR BY THE LEGUMINOS^ 21 . 



on the Leguminosce to a close in a manner which showed 

 that, in their opinion, the nodules contained bacteria. 



" The Leguminosce do not possess of themselves the 

 faculty of assimilating free atmospheric nitrogen ; the vital 

 action of the micro-organisms in the soil is absolutely in- 

 dispensable if this result is to be attained. In order that 

 free atmospheric nitrogen may aid in nourishing the 

 Leguminosa^, the mere presence of lower organisms in the 

 soil is not sufilicient ; it is further necessary that some should 

 enter into symbiotic union with the plants." 



M. Maze, Technical Director of the Laboratory of 

 Agricultural Chemistry at the Institut Pasteur, published in 

 1897, in the annals of that institution, a treatise on the 

 microbes in the nodules, which now^ leaves us with no 

 further doubt as to the existence of bacteria in the root 

 tubercles of the Leguminosas. 



M. Maze has succeeded in isolating these bacteria, that 

 is to say, in causing them to reproduce. Appended here- 

 with are the conclusions at which he arrived : — 



" The bacilli of the Leguminosce, when placed in a 

 suitable medium corresponding as closely as possible to the 

 natural conditions present in the nodules, grow in remark- 

 able fashion and at the same time discharge their important 

 function of fixing free atmospheric nitrogen. 



" Symbiosis is no longer necessary in order to explain 

 the fixation of free atmospheric nitrogen by the microbes 

 of root nodules; this is their special function, and perfectly 

 independent of any influence exerted by the plant. No new 

 force is evolved from the co-operation of these tw^o organisms, 

 the action of which is necessary in order to induce the free 

 nitrogen to enter into combination with organic or organized 

 complexes; and at the same time the hypothesis adopted 

 till now in order to explain the symbiotic mechanism, so 

 clearly expounded by M. Duclaux, remains unimpaired and, 

 further, receives the confirmation of practice. The plant 

 shelters an organism and supplies it with the carbohydrates 



