Macromolecules Regulating Growth and Development documents the proceedings of the 30th Symposium of the Society for Developmental Biology, held at the University of Washington in Seattle, June 17-19, 1971. The contributions made by researchers at the symposium are organized into three parts. Part I deals with regulatory factors in the selective growth of mammalian cells. It includes papers on the role of the cell surface in growth and transformation; the epidermal growth factor; and the role in regulation of tumor growth. Part II examines the formation and organization of plant cell walls and the plasma membrane. It presents studies on the origin and growth of cell surface components; synthesis and secretion of proteins in plant cells; and lipids and membrane structure. Part III deals with the organization and expression of genetic information. The contributions in this section include organization of DNA and proteins in mammalian chromosomes; total synthesis of transfer RNA genes; and biosynthesis of bacterial ribosomes.