Book excerpt: The Interpretation of Ulstrastructure is a collection of papers dealing with techniques in ulstrastructural research such as in fixation, reversed staining, ultrastructure in embryos and in plants, control of observations by light microscopy, and cytochemistry at the electron microscope level. One paper describes various fixatives used on rat liver tissue including a standard osmium tetroxide solution, pure melted osmium tetroxide, and strong osmium tetroxide solutions in carbon tetrachloride. Another paper points out that the use of electron micrographs of the cell nucleus and chromosomes should include approaches to chromosome analysis. For the investigator studying the three dimensional organization of chromosomes, his approaches should include classical cytology and cytogenetics, chemical and cytochemical studies on nuclei, as well as chemical and physical analysis of nucleic acid and nucleoprotein molecules. Several papers discuss the study of natural and artificial DNA-plasma by thin sections, an assessment of negative staining techniques for revealing ultrastructure, and other approaches in the study of biological ultrastructure by high-resolution electron microscopy. The collection will benefit microbiologists, biotechnologists, and academicians connected with the biological sciences.