This book was written during a period when the technologies of genetic engineering were being applied to the study of animal viruses and when the organization and function of individual virus genes were being elucidated. This book, which uses human and animal viruses as models, aims to under­ stand the developments in molecular virology during the last 20 years. Al­ though molecular virology could also be taught by means of bacteriophages or plant viruses, the advantage of using animal viruses is in their ability to cause human and animal diseases as well as to transform cells, a primary problem in medicine. For the sake of clarity and convenience, not all the individual contributors to the various aspects of molecular virology were cited in the text. Instead, the reader is referred to review articles or key papers that list the numerous excel­ lent publications that have contributed to clarification of the various molecular processes. Thus the end-of-chapter bibliographies will guide the reader to the publications in which the original contributing authors are quoted. References given under the heading Recommended Reading are intended to assist those interested in pursuing a given subject further. I hope that this book will fulfill the purpose for which it is designed, and I urge readers to contact me if errors are found or updating is required.

I. Molecular Aspects of Animal Viruses.- 1. Steps in the development of virus research.- 2. Classification of viruses.- 3. Molecular considerations of virus replication and virus-cell interactions.- 4. Genes in human cells determining virus susceptibility.- II. Virus Families.- A. Double-stranded DNA viruses.- 5. Poxviruses.- 6. Iridoviruses.- 7. Herpesviruses.- 8. Adenoviruses.- 9. Papovaviruses.- 10. Hepatitis B virus.- B. Single-stranded DNA viruses.- 11. Parvoviruses.- C. RNA minus viruses.- 12. Double-stranded RNA viruses made from single-stranded RNA: reoviruses.- 13. Single-stranded RNA minus viruses with an intact genome: rhabdoviruses.- 14. Single-stranded RNA minus viruses with an intact genome: paramyxovlruses.- 15. Single-stranded RNA minus viruses with a fragmented linear genome: orthomyxoviruses.- 16. Single-stranded RNA minus viruses with a fragmented linear genome: arena viruses.- 17. Single-stranded RNA minus viruses with a fragmented circular genome: bunyaviruses.- D. Viruses with single-stranded RNA plus genomes.- 18. RNA plus genome that serves as messenger RNA: picornaviruses.- 19. RNA plus genome that serves as messenger RNA: togaviruses.- 20. RNA plus genome that serves as messenger RNA: coronaviruses.- 21. Single-stranded RNA plus genomes that synthesize DNA as part of their life cycle: retroviruses (RNA tumor viruses).- E. Unclassified viruses.- 22. Marburg and Ebola viruses.- 23. Slow virus infections of the CNS.- III. Medical and Biological Considerations.- 24. Immunization against virus diseases.- 25. Viruses as selective forces in nature: epidemics.- 26. Antiviral drugs and chemotherapy of viral diseases of man.- 27. Laboratory diagnosis of disease-causing viruses.- 28. Viruses and human cancer.- 29. Social, economic, and juridical aspects of virus diseases.- IV. Summary.- 30. Summary.