Dr. Altschul has compiled field notes of health and medical interest on over 5,000 species of plants, culled from some 2,500,000 specimens of higher plants collected by field botanists from all over the world and deposited in the combined collections of the Arnold Arboretum and Gray Herbarium of Harvard University. The resulting catalogue represents a unique approach to supplying new investigational leads to researchers seeking biologically active plant principles. Dr. Altschul's meticulous sheet-by-sheet examination of the Harvard collections provides the pharmacognosist, pharmacologist, and others in the medical and health sciences with an extensive firsthand survey of the domestic medicines of many cultures.