“…This variation was an attempt to limit the phospholipolytic activity in the fractions prior to analysis, as suggested by Letters (1967) . Evidence for the quantitative nature of this extraction procedure has been provided by Letters (1966Letters ( , 1967 and Harrison and Trevelyan (1963) . Although peroxides were not measured directly in the lipid extract, major deterioration of lipids did not ap- $ Abbreviations: DPG, diphosphatidyl glycerol or cardiolipin ; PE, phosphatidyl ethanolamine ; PC, phosphatidyl choline or lecithin ; DMPE, dimethylphosphatidyl ethanolamine, PG, phosphatidyl glycerol ; PA, phosphatidic acid ; PS, phosphatidyl serine ; LPE, lysophosphatidyl ethanolamine ; PI, phosphatidyl inositol ; LPC, lysophosphatidyl choline or lysolecithin ; PLP, phospholipid phosphorus .…”