In the past few years, the body of experimental work on the structure, function and assembly processes of mihondria has expanded rapidly. No one person can believe himself or herself completely in control of the burgeoning literature without possessing serious omissions or blind spots. In the present monograph I have attempted a critical evaluation of the literature. I believe that the common thread of single authorship outweighs the shortcomings of one person presenting many disparate viewpo,ints. It is my hope that the end product represents a comprehensive and coordinated review of the subject matter to the present date. Although the bulk of this monograph was completed by October 1974, I have made some attempts to update several of the sections at later times. Albany, N. Y. , November 1975 H. TEDESCHI Contents A. Structure of Mihondria 1. General Organization . a) Conventional Thin Section Electron Microscopy b) Negative Staining Techniques . 3 c) Freeze-Cleavage . . . . . . . 4 2. Special Organization and Inclusions 10 a) Prismatic or Atypical Cristae 10 b) Filaments and Tubules . . 11 c) Amorphous Inclusions 12 d) Intramihondrial Granules 12 e) DNA Containing Fibers 14 3. Topography of the Mihondrial Transducing Systems 15 B. The Assembly of Mihondria 18 1. Mihondrial DNA and Its Genetic Role 19 2. Transcription of the Mihondrial DNA . 28 a) mRNA . . . . . . . . . . . . . . 30 b) The Machinery for Transcription and Translation 32 c) Turnover of Mihondrial RNA 36 3. Protein Synthesis . . . . . . . . 37 a) Mihondrial Protein Synthesis and Its Characteristics 37 b) Role of Mihondrial Protein Synthesis . .