Keep Off the Grass is a scientific inquiry into the scientific effects of marijuana. Marijuana, like most drugs ingested by man, gives the user the impression that his senses are enhanced, when in fact they have been distorted and impaired. This book is composed of 27 chapters, and starts with a brief introduction to the history of marijuana, the properties of its chemical components, called cannabinoids, and its widespread use and abuse. The succeeding chapters deal with the first scientific meetings on marijuana, social impact of marijuana, and its widespread use in some countries, such as in Morocco and Egypt. These topics are followed by discussions on the immunological and DNA effects of marijuana. The remaining chapters highlight the legal issues and government policies concerning the utility of this plant.