Effect of "osmotic" systems on germination of peas (Pisum sativum, L.).

1. It has been shown that the percentage germination of seed in contact with an aqueous solution depends (a) on the extent of differential permeability of the seed coat to the solute and (b) on whether the solute is toxic. 2. In investigations with "Meteor" pea seeds, polyethylene glycols of nominal molecular weights of 4000 or higher have proved to be suitable osmotic agents. 3. Solutions of sodium chloride, glycerol and mannitol may enter the seed with little restriction through micropyle and hence their influence on germination should not be ascribed to osmotic potential. 4. High concentrations of sodium chloride seem to be toxic to germinating peas. The glycerol solution on the other hand had no such toxic effect.