BOOK FUNDAMENTALS OF KERATINIZA- 'nON, edited by E. O. Butcher and R. F. Sognnaes. Publication No. 70, American Association for the Advancement of Science, Washing- ton, D. C. 1962. 189 pages, illustrated and indexed. Price $6.$0 ($5.75 to AAAS members). This small volume comprises papers presented at a symposium held by the American Association for the Advancement of Science in December, 1960. Most of these papers are original, and this volume is, therefore, of major interest to the workers in the field of keratin. The first paper in this book, by Matoltsy, is concerned with the role of keratohyalin in keratiniza- tion of mammalian epidermis. On the basis of histological studies, the author concludes that epidermal cells keratinize independently of one another and that tonofilaments and keratohyalin granules are differen- tiation products formed for in- corporation into the elaborated keratin. In another interesting chapter, Szab6 concludes that there is a difference between the embryonic and adult basal cells of the epider- mis: In the embryonic stage, these cells are self-differentiating, whereas basal cells in the adult epidermis are not self-differentiating. Rhodin and Reith, in their papers on the ultra structure of keratin again, return to the role of kerato- hyalin in keratinization. The pur- pose of keratohyalin has been in dispute ever since it was first dis- covered, and various workers have interpreted their observations dif- REVIEWS ferently. Mercer and his group have always maintained that kerato- hyalin is transformed into fibrils. These authors assign to keratohyalin a somewhat different role and in- dicate that keratohyalin aggregates with tonofilaments only during the formation of soft keratin. In con- trast, the formation of hard keratin and of amorphous keratin do not seem to require keratohyalin. Cosmetic chemists will be in- terested in the papers from a num- ber of groups concerned with the influence of Vitamin A on keratini- zation. Bern and Lawrence con- clude that the effect of Vitamin A on keratinizing epithelium varies as a result of dosage. On the other hand, Parnell and Sherman conclude that Vitamin A can be utilized directly by excised tissue and stimu- lates tissue mitotic activity at moderate dosage levels. One of the most interesting ob- servations in this volume concerns the one by Watson on the extracellu- lar position of dental enamel. Wat- son concludes on the basis of some beautiful electron photomicrographs that there is a cell membrane between the ameloblast and the enamel, indicating that enamel is fo•med extracellularly. Similarly, the last chapter of this book by Piez demonstrates that the protein matrix of enamel from human teeth, at least on the basis of amino acid composition, is not a true keratin and instead resembles collagen. It is equally interesting that this protein normally cannot be isolated unless the teeth have been treated with formaldehyde. 287

288 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS This volume, though relatively small, contains a wealth of interest- ing information and should be read and consulted by all interested in skin, hair, or teeth.--Martin M. Rieger, Warner-Lambert Research Institute. COLL^OE•r, edited by N. Ramana- than. IntersciencePublishers, New York, N.Y. 1962. 579 pages, illustrated. Price $20. Collagen is a compilation of papers presented in person or by corre- spondence at a Symposium in Madras, India, in November of 1960. Sponsoring agency was the Central Leather Research Insti- tute, Council of Scientific and Industrial Research. The symposium is divided into three main divisions: Structural Studies Medical and Biochemical Studies and Physical-Chemical and Technological Studies. Virtually every aspect of the theory and evidence concerning structure, physical chemistry and biological properties of collagen is discussed. Clinical and pathological conditions of collagen are not stressed. Many aspects of this volume are outstanding and impressive. For one thing, the list of major contrib- utors numbers 58, and they are drawn from all over the world and both sides of the Iron Curtain, in- cluding the United States, Russia, South Africa and India. The caliber of these investigations is very high and generally oriented toward the physical-chemical and molecular level. This reviewer, having served on the S. C. C. Special Award Committee for four years, was struck by the fact that not one of these numerous original investigators was ever nominated for the special award. It can be concluded that either interest in collagen or the amount of basic scientific reading by Society mem- bers is deplorably low. It is gratify- ing that this year's Award winner, Dr. Jerome Gross, is extensively quoted by many of the authors in Collagen. The highlights of the book are an excellent review of protein structure by G. N. Ramachandran, a thorough evaluation of the correlation of structure theory with X-ray dif- fraction and other evidence, O. Kratky's work correlating X-ray diffraction patterns with age of human tendon collagen, E. Kuhnke's presentation of collagen as a basis of tendon tissue function, and, especially for cosmetic chem- ists, K. T. Joseph's study on the influence of biological aging on the stability of skin collagen in albino rats. Each chapter has an extensive bibliography and an often penetrat- ing discussion section. English is used throughout, although many of the original manuscripts had to be translated from other languages. Despite this, not more than a half- dozen errors in text were found by this reviewer. Beautifully clear pictorial representation of collagen structure, electron micrographs and other tables abound. On the negative side, the lack of chapter sequential numbering and a subject index should be mentioned. A definite lack of continuity results from inclusion of a few papers on narrowly limited aspects of collagen. Occasionally, lack of sufficient in- troduction to a subject detracts from reader understanding. Over-all, this is a valuable sum- mation of current status of collagen research for the basic researcher in this field, especially the physical biochemist. For the cosmetic de- velopment chemist, this should be an interesting contribution to his understanding of skin, its structure and properties.--H. E. Jass, Revlon, Inc.