THE ACCUMULATION OF ELECTROLYTES : I. THE ENTRANCE OF AMMONIA INTO VALONIA MACROPHYSA

When 0.005 M NH(4)Cl is added to sea water containing cells of Valonia macrophysa ammonia soon appears in the sap and may reach a concentration inside over 40 times as great as outside. It appears to enter as undissociated NH(3) (or NH(4)OH) and tends to reach a pseudoequilibrium in which the activity of undissociated NH(3) (or NH(4)OH) is the same inside and outside. When ammonia first enters, the pH value of the sap rapidly rises but it soon reaches a maximum and subsequently falls off. At the same time there is an increase of halide in the sap which, however, does not run a parallel course to the ammonia accumulation, but it comes to a new equilibrium value and remains constant. The increase in NH(3) in the sap is accompanied by a decrease in the concentration of K. As NH(3) enters the specific gravity of the sap decreases and the cells rise to the surface and continue to grow as floating organisms. The growth of the cells is increased.