FROM THE MR BY THE LEGUMINOS.E 3I 



m£i\- be hindered in their functions by certain specific 

 causes which are, so it happens, encountered in growth in 

 the water. 



To brino- this brief account of HeHriepel and Wilfarth's 

 work to a close, we will summarize their final arguments, 

 based on the life of the plant, proving that the nodules 

 can in no way be regarded as receptacles for reserve food 

 supply. 



The growth cycle may be divided into three phases — 

 germination, growth, maturity. During germination the 

 plant develops aerial and subterranean structures by drawing 

 the necessary materials from its reserves, that is to say, from 

 the cotyledons. 



During growth an active assimilation of nutriment from 

 external surroundings takes place. A general growth of the 

 organs occurs, and the chief mass of the plant is formed. 



In the third phase the organs of fructification appear. 

 Assimilation diminishes and eventually ceases, and the whole 

 of the elements in leaves and roots are employed in nourish- 

 ing the plant till the time of its maturity. 



These three phases, however, have their periods of 

 transition, and the pi"ogress from one to another is a gradual 

 one. If the plant is situated in rich soil, the third period 

 is postponed ; assimilation is prolonged and the plant may 

 be said never to reach maturity. Should the soil be poor, it 

 is the second phase which changes; the plant is unable to 

 assimilate and lives on its reserves, in consequence the 

 organs are distorted and sickly and often fructification does 

 not take place. According to the authors of these researches, 

 it is this lack of assimihition which is the cause of inanition. 



It was proved that a soil infusion had no effect on cereals 

 living in a sterilized medium devoid of nitrogen, whilst it 

 often influenced Leguminos^e. These latter, however, often 

 experienced a period of inanition, even when the soil extract 

 was incorporated before sowing. Germination having taken 

 its normal course, those plants which had been treated with 



