The early development of the mammalian embryo belongs to a period which, for the student, provides the particularly deep fascination connected with the processes of germination of the fIrst tender buds of life. Moreover, developmental biology encompasses a very large part of biology; if broadly dermed - almost all of it. The same is true for the fIeld of pathology if the manifold possibilities of disorders of the orderly arranged pathways of developmental processes are considered. Normal development in its earliest steps - and it would be diffI cult to see it otherwise - means the functioning of very intricate systems of complex inter dependent cycles controlled by structural, genetic, physiological and biochemical determi nants. However, disturbances interfering with them in their very different ways, can lead to fetal death, disorders of growth and differentiation, malformation and disease, sometimes as late as in the next generation or later. This is, indeed, the concern of the pathologist to whom and to whose interest in developmental pathology, this book is dedicated. The outlines of the present volume were conceived at a symposium on "Control of early em bryogenesis and factors responsible for failure of embryonic development" held May 1-4, 1974 in Travemtinde and sponsored by the Deutsche Forschungsgemeinschaft. Almost fIfty active participants attended this conference. At the time and in keeping with the purpose of the conference, publication of the proceedings was not envisaged."

Laboratory Animal Medicine has made enor We deeply appreciate the efforts of each of the mous strides in the 47 years since R. Jaffe published authors and co-authors of the 23 chapters in this his "Anatomy and Pathology of Spontaneous Dis two volume work. In some instances the reader will eases of Small Laboratory Animals" in 1931. So note what appears to be repetition in certain chap ters. This repetition was allowed to stand in some much new information had accumulated that in a cases because different approaches seemed useful, new edition in 1958, Jaffe, aided by Cohrs and Meessen, needed the assistance of 46 colleagues to although efforts were made to delete most of the do the subject justice. Like its predecessor, this two redundancy which inevitably arises in a venture of volume comprehensive treatise on "Pathologie der this kind. We will be grateful if our colleagues point out errors and send us specific and general Laboratoriumstiere" was written in German and criticism of this work to allow corrections in the thus not readily available to the widening circle of event of reprinting or a next edition. veterinarians and pathologists who now are inter One objective has been to assemble current in ested in laboratory animals. Aside from the need to have a comprehensive formation in the pathologic aspects of diseases of review of laboratory animal pathology in English, laboratory animals."

This presentation of the diseases of the placenta differs in many ways from the first such treatment in these volumes by the eminent Robert Meyer. It is a deliberate attempt to bring together the practical information which has been gathered about the pathology of this complex organ and to make it available to the practicing pathologist as well as clinician. Despite the ready availability of the placenta for study, the pathologist is often ill-prepared to interpret lesions which he may find. Moreover, it has been difficult for him to find reference material, published commonly in journals and books with which he is not familiar. Further more, the interpretation of lesions affecting the placenta seemed less challenging since the organ had served its function, was to be discarded and presumably little of significance could be expected from such a retrospective study. Recently, with new emphasis on maternal and fetal health and disease, it has become apparent that knowledge of pathologic changes in the placenta often provides a unique insight into antenatal events. Thus, there has been an abundance of publications in this field in recent years, several in book form. These and the most important older investigations on the morbid anatomy of the human pla centa are here reviewed. This book has been written with a special point of view, however, which reflects our own bias."

This conference represents the first time in my life when I felt it was a misfor tune, rather than a major cause of my happiness, that I do conservation work in New Guinea. Yes, it is true that New Guinea is a fascinating microcosm, it has fascinating birds and people, and it has large expanses of undisturbed rainforest. In the course of my work there, helping the Indonesian government and World Wildlife Fund set up a comprehensive national park system, I have been able to study animals in areas without any human population. But New Guinea has one serious drawback: it has no primates, except for humans. Thus, I come to this conference on primate conservation as an underprivileged and emotionally deprived observer, rather than as an involved participant. Nevertheless, it is easy for anyone to become interested in primate conserva tion. The public cares about primates. More specifically, to state things more realistically, many people care some of the time about some primates. Primates are rivaled only by birds, pandas, and the big cats in their public appeal. For some other groups of animals, the best we can say is that few people care about them, infrequently. For most groups of animals, no one cares about them, ever.

Pathology of the Human Placenta remains the most comprehensive and authoritative text in the field. It provides extensive information on the normal placenta, encompassing physiology, metabolism, and endocrinology, and covers the full range of placental diseases in great detail. Further chapters are devoted to abortions, molar pregnancies, multiple pregnancies, and legal considerations. This sixth edition of the book has been extensively revised and expanded to reflect the most recent progress in the field, and a brand new chapter has been added on artificial reproductive technology. Some 800 illustrations are included, many of them in color. The detailed index has been further improved and tables updated. Pathology of the Human Placenta will be of enormous value to pathologists and obstetrician-gynecologists alike.

Since the publication of the first Atlas of Mammalian Chromosomes in 1967 the continuous compilation of mammalian karyotypes has become a useful instrument in cytologic and taxonomic studies. Technical advances in preparing mitotic cells from nonmammalian vertebrates have since allowed a better comparison of taxa in fishes, amphibia, reptiles, and birds. In these fields the literature is also widely scat tered; and it has become difficult to survey such information, published as well as unpublished, by nonspecialists. These were among the reasons for the new endeavor of compiling a chromosome atlas for nonmammalian vertebrates. An annual publication is planned with presentation of between 10 and 15 karyotypes from each class. In this second volume, 52 species are presented. For convenience in future colation, the numbering system employs class abbreviations, viz., P-Pisces, Am-Amphibia, R-Reptilia, and Av-Aves. Within each class, the numbers are necessarily consecutive. In general the karyotypes are laid out following the format employed in An Atlas of Mammalian Chromosomes. Whenever possible both sexes are represented, even though sexual chromosomal dimorphism is not (currently) evident. When the sex chromosomes are known, they are so indicated by conventional nomenclature (XX/XY or ZW /ZZ). In the karyotypes of birds the so-called microchromosomes are grouped together at the end without an attempt at complete enumeration, which is presently impossible. They are usually considered as acrocentrics, but a few are distinctly biarmed."

In recent years, because of advances in karyological techniques, we have witnessed a remarkable renewal of interest in studies of mammalian chromosomes. These techniques, generally involving the use of tissue culture, colchicine and hypotonic solution pretreatments, allow for a much clearer display of metaphase chromosomes of mammalian cells than the classic direct squash or tissue section methods. Consequently, what was known about the chromosome complement of most mammals must be revised. The most astonishing revision, of course, was that made by Tjio and Levan in 1956, who demonstrated that the diploid number of man is 46, not 48 as previously believed. Similar revisions will have to be made for many other mammalian species, either in number or in karyotype structure. Many animals are being examined cytologically for the first time. The findings are now extensive and scattered; they appear in numer ous periodicals and newsletters, or they are kept in cytologists' file drawers without being published. It is difficult to have access to perti nent data for comparison among related species or for evaluation of various karyological characteristics within a karyotype. Such evaluations can be done only when reasonably uniform material is collected and placed side by side for comparison, accompanied by relative references. We considered that probably an Atlas of Mammalian Chromosomes would fulfill such a need. Needless to say, it is impossible to present karyotypes of all mam malian species at one time.