Importance of ‘ Nitragin! 515 
of the plants with and without inoculation, the pods borne 
by inoculated plants were ripening more quickly than those 
borne by the plants without inoculation. 
This observation lends support to the view recently put 
forward by Mattirolo 1 that the root-nodules are organs for 
the elaboration of the albuminous materials required in the 
formation of the seeds. He found that if the formation of 
the fruit was prevented by the removal of all the young 
flower-buds, the contents of the nodules were not absorbed 
by the plants ; whilst on the contrary the plants producing 
a normal quantity of fruit bore nodules which were com- 
pletely emptied of their reserve stores of albuminous sub- 
stances. 
In the experiments on unsterilized media the plants were 
arranged — 
1. In a parallel series of three sets of crops, grown in the 
summer of 18 99, upon ordinary garden-soils and a gravelly 
subsoil with and without inoculation with ‘ Nitragin ’ and with 
and without an additional supply of nitrogenous food in the 
form of potassium nitrate. 
2. In a series of crops grown in the summer of 1900, on 
ordinary garden-soil, clay, peat and loam, in order to test the 
effect of inoculation with ‘ Nitragin ’ on media of different 
chemical corrfposition. 
As before the plants were allowed to grow until the pods 
were ripened, and records were then made of the numbers 
of infections and the dry weight of the crops. 
These open-air experiments, which involved the cultivation 
of nearly 700 plants, led — like those conducted on sterilized 
media — to a very unfavourable conclusion as regards the 
practical value of ‘ Nitragin.’ The nodule-organisms were 
found to be present in all types of soil, though they seem to 
be less abundant in clay and peat, and in these particular 
soils alone a large increase in the number of infections resulted 
from inoculation with ‘ Nitragin.’ 
1 Mattirolo, ‘Sulla Influenza che la Estirpazione dei Fiori exercita sui Tubercoli 
radicali delle Piante Leguminose/ 1900. 
M m 
