The nature of the intramembraneous particle.

It is argued that the different modes of fracturing of the erythrocyte membrane and the outer membrane of Escherichia coli with respect to the intramembraneous particles have their definite biochemical and structural counterpart i.e.,. the non-complementary particles of the erythrocyte membrane being predominantly proteinaceous in nature and the complementary particles of the outer membrane of E. coli being determined by lipopolysaccharide. Evaluation of the complementarity aspect of intramembraneous particles shows than an assessment of complementarity in replicas may decisive when interpreting micrographs at the macromolecular level.