This volume contains the proceedings of the International Symposium on Function and Biosynthesis of Lipids held November 1976 at Sierra de la Ventana, Argentina. The conference was organized by the Argentine Biochemical Society and co-sponsored by the International Union of Biochemistry and the Pan American Association of Biochemical Societies. The Symposium’s great success is owed to all the participants, most of whom were actively involved in the interesting and stimu- lating discussions that followed every single lecture and communi- cation delivered. Many thanks also to Drs. R. Anderson, S. Bonting, K. K. Carroll, B. Cecarelli, M. A. Crawford, R. T. Holman, J. Mead, R. H. Michell, G. Porcellati, W. Stoffel, W. Thompson, and H. Wiegandt for chairing Symposium sessions. The contributions are organized in four sections, preceded by the opening lecture on the role of dolichol phosphate in glyco- protein biosynthesis delivered by Dr. Luis F. Leloir. The first section, on aspects of lipid involvement in the biogenesis of mem- branes, covers the biosynthesis of saturated and unsaturated fatty acids, including enzymology, biosynthetic pathways, and regulation and modifications during development, in the fetus and in tumor~ cells. Papers on the composition and assembly of membrane compo- nents, lipid interactions with proteins and enzymes, developmental changes of lipids, and newer approaches to survey the organization and biogenesis of cellular membranes complete this section. New information as well as reviews of current concepts about structural specificity, biosynthesis, and function of glycosphingo- lipids are included in the second section.