30 T. L. Lyon anp J. K. Witson 
solution and in the deposit, but whether it would account for all of the 
former may be questioned. | 
It was when the solution remaining in the flask was reduced to a rather 
small volume that the quantity of organic nitrogen in the solution fel 
decidedly. However, it did not appear that this was due to the saturatior 
of the solution, as the large flask no. 1291, which contained 3700 cubi 
centimeters of solution at harvest, had no more organic nitrogen in thx 
solution than did the smaller flask no. 1286, which contained only 150( 
cubie centimeters of solution when opened. 
It seems likely that the organic nitrogenous compounds are absorbes 
by the plant as it approaches maturity. This may be in order to establis) 
equilibrium between the plant juices and the solution in which the root 
are immersed. In the soil there would probably be a tendency for thes 
organic nitrogenous compounds to undergo ammonification and _nitrif 
cation, and, if conditions are favorable for these processes, there migh 
be very little organic nitrogen in the soil solution at any time. Cor 
sequently, if there is a tendency to establish osmotic equilibrium thei 
would probably be a much greater removal of organic nitrogen fror 
a plant growing in soil than from one growing in a sterile solution. 
Organic nitrogen appears in the nutrient solution before all of tk 
nitrate nitrogen has disappeared, but the disappearance of nitrates 
not a signal for the decided drop in organic nitrogen which occurs muc 
later. 
Previous investigations concerning the liberation of nitrogen frog 
higher plants during growth have been conducted in two ways. O1 
of these consisted in analyzing the plants from a measured area of larg 
at certain intervals in the growth of the plants. Such experiments usual 
demonstrated that there was a loss of nitrogen from the plants betweig 
blossoming and ripening. Owing to the fact that the plants were absorbug 
nitrogen rapidly at earlier stages of growth, the income was greater thi}. 
the outgo and consequently the earlier movement of nitrogen was n 
discovered. The other method, used by Le Clere and Breazeale, in whi 
the leaves were washed, showed a removal of nitrogen at each stage | 
which it was applied, but naturally the loss so occasioned would be rath 
small under natural conditions as it would occur only during perio 
of rainfall or heavy dew. 
