||p.732 2nd paragraph:"The data shown in Table 1 can be interpreted to indicate that there are three general classes of membranes. The simplest membrane system is myelin, whose main function is to act as an insulator. Accordingly the major membrane component is lipid, and there is very little protein. Since there are only two known enzymatic functions associated with myelin (refs 19-21), the small amount of protein in this membrane is not surprising. [Investigators] can thus imagine that all membranes would resemble myelin in their composition if their only function were to be, a permeability barrier." p.733 3rd paragraph:"How the proteins are arranged in the membranes cannot be determined from
the data shown in Table 1."