“…Schoffeniels (114a) described the permeability characteristics of animal and human tissues and cells primarily for substances occurring in their natural environment and also discussed the electrical properties and structures of these membranes. Symposia, conferences, or special issues were devoted to particular as pects of passive permeability (61,101,121,140,145); to the plasma mem brane [( 37) with an excellent contribution on the history of the plasma mem brane concept (74a, 96, 116»); to biophysics and physiology of biological transport and cell membranes (5,113) ; to colloid chemistry, ultrastructure of membranes, and active uptake (150); and to membrane structure and function (3a, 107, 141a). Biophysics of permeability (74) and transport and distribution of material in cells of higher plants (105) were discussed in meetings scheduled for 1968.…”