On Molecular Biology.- References.- The Biological Significance of the Genetic Code.- I. Introduction.- II. Characteristics of the Genetic Code.- III. Conclusion.- References.- Errors in Translation.- I. Introduction.- II. The Translation System.- III. Errors in Translation.- IV. Errors Produced by Aminoglycosides.- V. Ribosome Mutations Leading to Ambiguity.- VI. Other Factors Causing Ambiguity in vitro.- VII. Does Misreading Occur in Mammalian Systems ?.- VIII. Does Misreading Occur in Living Cells?.- IX. Finale.- References.- The Incorporation of Fluorouracil into RNA and its Molecular Consequences.- I. Introduction.- II. Incorporation of FU into Whole Cells and Tissues.- III. FU and Ribosomes.- VI. FU and sRNA.- V. FU and mRNA.- VI. FU and Protein Synthesis.- VII. Synthetic Polynucleotides Containing FU.- VIII. Discussion.- XI. Summary.- References.- Organelle Biosynthesis: The Chloroplast.- I. Introduction.- II. Composition.- III. Chloroplast DNA.- IV. Ribosomes and RNA.- V. Synthesis of Chloroplast Proteins.- VI. Photoregulation of Chloroplast Development.- VII. General Conclusions.- References.- Macromolecules and Brain Function—A 1969 Baedeker.- I. Introduction.- II. Growth.- III. Sensory Modalities.- IV. Structural Localization: Brain Regions and Fractions.- V. Human Disorders.- VI. Learning and Memory.- References.- Author Index.