Biogenic toxins are fascinating natural products characterized by an enormous diversity of chemical structures and pharmacological activities. They not only pose hazards to humans and animals, but they are important components in the interplay of substances and living beings in nature and, moreover, important sources for new drugs. The present book is the first volume of the 5-volume series "Natural Poisons and Venoms". Volumes 1-3 cover poisons produced by plants, volume 4 summarizes poisons and venoms of animals and volume 5 deal with poisons of fungi, cyanobacteria, and other microorganisms. This volume starts with a fundamental chapter on history, chemistry and pharmacology of natural toxins, importance of the toxins for their producer, potential danger for humans and animals, and general aspects of toxicology including notes for first aid and proposals for clinical measures. The following chapters focus on the poisonous representatives of terpenes and the related steroids. The reader will be informed about the botany and occurrence of plants producing these toxins, the chemistry, the biogenesis and the pharmacology of the toxins, possible causes of poisonings, precautions to avoid poisonings, symptoms of poisonings of humans and animals, proposals for treatment measures and the possible usefulness, in the past, in present and in the future, of these toxins, especially for the development of new medicines. Numerous images of plants and chemical structural formulas complete the book. Extensive lists of literature references are given. The handbook is intended for physicians, veterinarians, pharmacists, chemists, biochemists, food chemists and biologists, for the students in the relevant fields, and also for interested laymen. You will be informed about all aspects of natural toxins based on the latest knowledge.