Protoplasmic streaming theory of translocation of organic solutes was first proposed by

The protoplasmic streaming theory of translocation of organic solutes was first proposed by de Vries.
Hugo Marie de Vries was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes.
Cytoplasmic streaming, also called protoplasmic streaming, is the movement of the fluid substance (cytoplasm) within a plant or animal cell. The motion transports nutrients, proteins, and organelles within cells.