FROM THE AIR BY THE LEGUMINOS.E 3/ 



In view of the confirniiition which this thet)ry has just, 

 in some sort, received from Hungary, M. Henry is of the 

 opinion that it is not one to be dismissed without discussion. 

 Consequentlv, in order to put Jamieson's theory on a firm 

 foundation, lie determined to cultivate trial plants in a limited 

 atmosphere of known volume, and absolutely devoid of 

 nitrates and of ammonia ; just as AIM. Schloesing and 

 Laurent did witii peas and tobacco. Analvsis of the gases 

 showed that after three months' growth a certain volume 

 of nitrogen had disappeared, having been fixed by the 

 plants or soil, and an analysis of the plants showed that 

 precisely the corresponding amount of nitrogen had been 

 gained. 



It is in this vein that M. Henry concludes his criticism, 

 and he adds that if the plants possessing these nitrogen- 

 fixing organs give similar results, the absorption of primary 

 atmospheric nitrogen will be a proved fact. Till then we 

 will take as our foundation in determining the physiological 

 character of the Leguminos^e the work of Hellriegel and 

 Wilfarth. This decision is rendered easy by the numerous 

 researches of various scientists on the formation of root 

 nodules, as well as on the evolution of races among the 

 bacteria of the Leguminos^. 



Formation of Root Nodules. 



Like all other bacteria, the bacteria fotmd in root nodules 

 are present in the atmosphere, in water, and in the soil. 

 They appear to be attracted by carbohydrates in the piliferous 

 region of the roots. They enter through hair cells, repro- 

 duce, and spread along a sort of channel as far as the cells 

 of the cortex. The cells divide and viscous matter is secreted 

 by the bacteria, which is disseminated through a series of 

 small channels of infection. This viscous matter, a product 

 of bacterial katabolism, is carried along by the sap and can 

 then be assimilated. Such is the explanation put forward 

 by M. Ka^'ser. 



