This book, an outgrowth of a series of films done by Evan Valens and Dr. Stanley along with six staff members of the Virus Laboratory at the University of California, is a timely, up-to-date study of viruses and their effects. Among other clear and comprehensive facts, we learn that viruses cannot be directly observed, that the only conclusive proof of their presence is in tissue damaged or destroyed by them. Is the virus a living organism? Apparently this can be argued endlessly, the concluding result being that it resembles both living and inert organisms. How the virus operates as a disease and a killer is described in detail. An analysis of man in terms of his atoms, and an examination of protein and nucleic acid, the two properties of viruses are related, and indicate that viruses, cancer, genes, and life itself are all dependent on the structure of nucleic acid.