The 63 articles collected in this book appeared in the news and reviews section of Nature between January 1969 and August 1970. These short essays, written by the journal's specialist correspondents, summarize the most important and interesting pieces of research in molecular and cell biology, virology, and biochemistry. They represent a completely new genre, which has grown out of Nature's unique amalgam of learned journal and weekend magazine for scientists. The book is therefore neither a catalogue of facts nor a review of research, but rather a unique journalistic approach to an exciting part of professional science.