Blood Vessels

This excellent monograph by Phillippe Sengel brings together an enormous body of data on the embryonic development of the skin in mammals, birds, and reptiles, and most of the information available on the many chemical factors and tissue interactions which produce these changes. The book is divided into four sections. The first describes the histogenesis of developing skin visible with the light or electron microscope. In addition to the discussion on epidermis, a substantial amount of information is presented about the histogenesis of the dermis, hair and feathers. The second section compiles the data on proliferation of the epidermal cells; the many chemical regulators of cellular division such as chalones, prostaglandins, and epidermal growth factor; and the effect of epidermal-dermal interaction on basal cell mitosis. The section concludes with a superb discussion on the relationship of cellular proliferation to topography, and architecture of the epidermis, hair and feathers. The third part presents the histologic features of cellular differentiation within the epidermis and the identified regulators of cellular differentiation such as dermalepidermal interactions, vitamin A and hydrocortisone. Section four synthesizes the data to show the mechanisms by which these two processes, cellular proliferation and differentiation, combine to form the final product, i.e., the skin of the neonate. The presentation on morphogenesis of the hair and feathers, the author's specialties, are especially complete and well done. The book is excellent in most respects. The author deserves special credit for including sections on the development and formation of the dermis, a forgotten portion of the skin. The author is an expert in the field and is able to present a wide range of data in clear, concise fashion. The book will be of most value to developmental biologists and dermatologists, or other physicians with a particular interest in diseases of keratinocytes and keratinization such as psoriasis or ichthyosis; diseases affecting dermal-epidermal interaction such as epidermolysis bullosa; or hair formation such as monilethrix. The single valid criticism of the book should be directed at the publisher. The author compiled the data on development of the skin up to 1973. He completed and dated his introduction to the monograph in May 1974, but the book was not published until late 1975, almost two years' delay during which time substantial amounts of new data became available. Despite this criticism, the book is worth obtaining for those seeking detailed information on the morphogenesis of the skin. JAMES J. NORDLUND Department of Dermatology Yale University School of Medicine