Rohrbach presents a book for physicians and students in which skin diseases are grouped on biologic rather than morphologic lines. The book is composed of a general part, in which the various subjects are handled in much the same manner in which they are treated in the American textbooks, and a special part, divided into conditions of known etiology, under which is included the infectious skin diseases, embracing a discussion of the pyoderms, fungous and parasitic infections and other infectious conditions of the skin, and hereditary skin diseases, in which the significance of heredity in dermatology is discussed. The latter is grouped into dominant and recessive skin diseases. Under dominant the author classifies epidermolysis bullosa hereditaria, ichthyosis vulgaris, ichthyosis congenita universalis, neurofibromatosis, Darier's disease, keratoma palmare et plantare hereditarium, acne vulgaris, porokeratosis, vitiligo and rosacea. Xeroderma pigmentosum is the only condition classed as recessive. The section on allergic skin diseases