unit-membrane modela model for the CELL MEMBRANE in which the membrane consists of a central lipid layer sandwiched between two layers of protein. See Fig. 309 . The unit-membrane model was proposed in the 1950s by the American physician David Robertson, who found his ELECTRON MICROSCOPE studies tallied with deductions reported by H. Davson and James Frederick Danielli in the 1930s. More recently the FLUID-MOSAIC MODEL has come to be more generally accepted.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005