For ten days, a number of neuroscientists met at Reisensburg to attend a series of lectures and discussions, an Institute, on animal learning. The students were drawn from a wide variety of disciplines, including anatomy, biochemistry, pharmacology, physiol ogy and zoology. It is probably true to say that many of them had at best a sketchy knowledge about the learning behavior of animals, about the conditions which are necessary for learning to take place and about the theories that psychologists have constructed about the learning processes. Was the Institute of any benefit to those neuro scientists whose interests lay in studying the functioning of the nervous system by manipulating it or probing it in some direct way? Some twenty years ago the answer to this question would probably have been "No"; and there is a very good reason why this view might have been held, especially by students of the mammalian nervous system. At that time most investigators used anaesthetised animals, or animals immobilized in some other way such as by surgically isolating the brain from the spinal cord, by dividing the brain at various levels or through the use of paralyzing agents. These con ditions achieved two things. On the one hand, they allowed sub stantial advances to be made, particularly in the analysis of sensory processing and in the analysis of the neuronal mechanisms of relatively simple reflex action. On the other hand, the experi mental conditions virtually eliminated complex behavior."

Perhaps no scientific field in recent years has gained in techniques and applications as much as molecular biology, and it is certainly no ex aggeration to.say that among all the applications of molecular biology, hematology in general, and hemopoiesis in particular, have benefited most. Owing to the applications of molecular biology, we now live in a golden era of hemopoiesis. Our understanding of the intricate regulatory system in hemopoiesis has vastly expanded. The potential for future exploration is ever expanding, and finally, the possibility of gene manipulation, has provided the promise of fundamental treatment and "cure" of many genetic disorders involving hemopoietic cells. In the ambiance of this rapidly moving scientific era, the necessity for review of what is being accomplished and where the technical potential is taking us needs no argument. This volume presents the proceedings of the third annual symposium on the Molecular Biology of Hemopoiesis, held in the Rye Town Hilton, New York, November 6 and 7, 1987, under the auspices of New York Medical College, Valhalla, New York. The fact that this was the third regular symposium covering this area in itself testifies to a need for exchange of the rapidly developing knowledge in this area. But this third symposium also coincided with the centennial of the National Institutes of Health and consequently the symposium was dedicated to this festive occasion."

This book is directed at advanced undergraduate and postgraduate students-and their teachers-who are involved in those areas of cell biology which require a basic knowledge of cytoskeletal structure, parti cularly with respect to cell motility. It contains a core of basic information on the cytoskeleton and focuses especially on its functional aspects, from the swimming of spermatozoa to the crawling of cultured cells across their culture dish; from the transport of vesicles and organelles along nerve axons, to the orderly segregation of chromosomes at mitosis. Cytoskeleton research spans a wide range of scientific disciplines. I t is as important for students or research workers investigating, for example, the deposition of the higher plant cell wall to have easy access to a core of basic information regarding microtubules as it is for someone interested in endocytosis and the fate of cell surface receptors. The authors are involved in the teaching of the cytoskeleton and cell motility at all levels of undergraduat~ study at University College London, but each has a research interest in different aspects of the subject: TMP in amoeboid locomotion, CAK in gliding motility and JSH in cilia, flagella and mitosis.

This series was established to create comprehensive treatises on specific topics in developmental biology. Such volumes serve a useful role in developmental biology, which is a very diverse field that receives contributions from a wide variety of disciplines. This series is a meeting ground for the various practi tioners of this science, facilitating an integration of heterogeneous information on specific topics. Each volume is comprised of chapters selected to provide the conceptual basis for a comprehensive understanding of its topic as well as an analysis of the key experiments upon which that understanding is based. The specialist in any aspect of developmental biology should understand the experimental back ground of the specialty and be able to place that body of information in context, in order to ascertain where additional research would be fruitful. The creative process then generates new experiments. This series is intended to be a vital link in that ongoing process of learning and discovery."

The 13th Annual Meeting of the Foundation was held in Edinburgh during September 1985. The subject was neuroendocrine molecular biology which brought together leading scientists in the fields of molecular genetics, neuroendocrinology and developmental neuro biology. The conference was most stimulating and as the Proceedings show, novel data presented was of the highest quality. The topics presented were grouped under the headings;, "Molecular Biology of the Nervous System," ''IlIRH - New Perspectives', ''Neuropeptides'', "Oxytocin and Vasopressin," "Transcriptional and Post-Translational Regulation of Neuropeptide Synthesis," "Neuroendocrine Mechanisms at the Cellular Level," "Receptors - Cellular and Molecular Biology" and "Clinical Applications." The"

Historical Remarks Bearing on the Discovery of Pan paniscus Whether by accident or by design, it was most fortunate that Robert M. Yerkes, the dean of American primatologists, should have been the first scientist to describe the characteristics of a pygmy chimpanzee, which he acquired in August 1923, when he purchased him and a young female companion from a dealer in New York. The chimpanzees came from somewhere in the eastern region of the Belgian Congo and Yerkes esti mated the male's age at about 4 years. He called this young male Prince Chim (and named his female, com mon chimpanzee counterpart Panzee) (Fig. I). In his popular book, Almost Human, Yerkes (1925) states that in all his experiences as a student of animal behavior, "I have never met an animal the equal of this young chimp . . . in approach to physical perfection, alertness, adaptability, and agreeableness of disposition" (Yerkes, 1925, p. 244). Moreover, It would not be easy to find two infants more markedly different in bodily traits, temperament, intelligence, vocalization and their varied expressions in action, than Chim and Panzee. Here are just a few points of contrast. His eyes were black and in his dark face lacked contrast and seemed beady, cold, expressionless. Hers were brown, soft, and full of emotional value, chiefly because of their color and the contrast with her light complexion."

In recent years there has been an explosion in research on the papillo- maviruses. The viral nature of human warts was first suggested 80 years ago by Ciuffo, who demonstrated transmission using cell-free filtrates. Shope described the first papillomavirus over 50 years ago as the etiologic agent in infectious papillomatosis in rabbits. Subsequent studies by Rous established that benign rabbit papillomas induced by this virus could progress to carcinomas when treated with specific nonviral cofactors. Despite these rich beginnings, the papillomavirus field lay virtually dor- mant until the late 1970s because no one was able to propagate these viruses in culture successfully. In the late 1970s the molecular cloning of the papillomavirus genomes permitted investigators to partially cir- cumvent this obstacle to their progress. The cloning of the viral genomes permitted the standardization of viral reagents and provided sufficient material to begin a systematic evaluation of the biology of this group of viruses.

Marsupials are excellent objects for studies on developmental processes in all mammals including humans. Marsupials are very immature at birth and undergo most of their development in a pouch where they can be manipulated in a variety of ways without affecting the mother. Most of these studies are on systems which largely mature before birth in eutherian mammals and are consequently difficult to investigate. Attention is also drawn to certain features peculiar to adult marsupials: e.g., they continue to grow throughout adult life, valuable for studies on growth mechanisms, and furthermore the composition of marsupial milk changes radically through lactation, most important in studies of hormonal regulation of milk composition and secretion.

"Theorizing about brain functions is often considered slightly disreputable and anyhow a waste of time -perhaps even 'philoso- ical'" 1 P. S. CHURCHLAND At present there are no unanimously accepted general con cepts of brain operation and function. This is especially the case with regard to so-called "higher" functions such as per ception, memory or the coupling between sensory input and motor output. There are a number of different reasons for this. Some may be related to experimental limitations allowing the simultaneous recording of the activities of only a restricted number of neurones. But there are also conceptual difficulties hindering the transition from "single-neurone" schemes, in which neurones are assigned relatively specific tasks (such as feature detection), to more complex schemes of nerve cell as semblies (for a discussion of some of the difficulties see Abeles 1982; von der Malsburg 1981; Kriiger 1983). Whilst much is known about the basic properties and functions of single neu rones, whose operations we hope to understand in the foresee able future, this does not hold true in the same way for the working of large assemblies of neurones.

Twenty years ago the discovery that Vibrio cholerae does not "die off" in the environment was made. We hypothesized that this gram-negative, rod-shaped bac- terium possessed the capacity to survive for very long periods of time, i. e. , months or years, under conditions adverse to active growth and reproduction. The term "somnicell" was proposed in 1987 to describe this state of being. Subsequently a series of experiments showed that this phenomenon was not unique to Vibrio chol- erae. Many other gram-negative bacteria were found to undergo the "viable but not culturable" state in response to adverse environmental conditions. Such bac- terial species included Escherichia coli, Salmonella enteriditis, Campylobacter je- juni, Legionella pneumophila, and Shigella sonnei, among others. Clearly, the ability to tolerate the vicissitudes of the environment, notably changes that accom- pany climate and season, is part of a strategy for survival that is pervasive among bacterial species that are both aquatic in natural habitat and opportunistic human pathogens. It raises a question as to whether the pathogenicity manifested by these bacteria is opportunism, or simply metabolic functions of bacteria that are naturally occurring in the environment and contributing to the stability and sustainability of the environment, with the inadvertent host, the human, suffering because of mis- placed consequences of those metabolic functions. It is an interesting question to ponder. Throughout the pages that follow, invited authors describe, from each of their perspectives, the significance and consequences of the viable but nonculturable state.

This volume of the series The Plant Viruses is devoted to viruses with rod-shaped particles belonging to the following four groups: the toba moviruses (named after tobacco mosaic virus), the tobraviruses (after to bacco rattle), the hordeiviruses (after the latin hordeum in honor of the type member barley stripe mosaic virus), and the not yet officially rec ognized furoviruses (fungus-transmitted rod-shaped viruses, Shirako and Brakke, 1984). At present these clusters of plant viruses are called groups instead of genera or families as is customary in other areas of virology. This pe culiarity of plant viral taxonomy (Matthews, 1982) is due to the fact that the current Plant Virus Subcommittee of the International Committee of Taxonomy of Viruses is deeply split on what to call the categories or ranks used in virus classification. Some plant virologists believe that the species concept cannot be applied to viruses because this concept, according to them, necessarily involves sexual reproduction and genetic isolation (Milne, 1984; Murant, 1985). This belief no doubt stems from the fact that these authors restrict the use of the term species to biological species. According to them, a collection of similar viral isolates and strains does constitute an individ ual virus, i. e., it is a taxonomy entity separate from other individual viruses."

This volume is one of those published from the proceedings of the invited lectures to the First International Congress of Comparative Physiology and Biochemistry I organized at Liege (Belgium) in August 1984 under the auspices of the Section of Comparative Physiology and Biochemistry of the International Union of Biological Sciences. In a general foreword to these different volumes, it seems to me appropriate to consider briefly what may be the comparative approach. Living organisms, beyond the diversity of their morphological forms, have evolved a widespread range of basic solutions to cope with the different problems, both organismal and environmental with which they are faced. Soon after the turn of the century, some biologists realized that these solutions can be best comprehended in the frame work of a comparative approach integrating results of physiological and biochemical studies done at the organismic, cellular and molecular levels. The development of this approach amongst both physiologists and biochemists remained, however, extremely slow until recently."

If it is still true that more than 80% of the ornithologists in North America are primarily interested or engaged in ecological studies on birds (J. R. King and W. J. Bock, Final Report of the Workshop on a National Plan For Ornithology, 1978), then Volume 3 of Current Orni thology is preadapted for their consideration. All but one article in this volume are somehow concerned with the ecological aspects of the bi ology of birds. Variation in the scope of topical coverage is relatively broad, and includes conservation, reproduction, behavior, community structure, and evolutionary ecology. Three reviews concern the pervasive effects of man and industry on various bird populations of the world. Risebrough provides a de tailed description of the relationships between pesticides and bird pop ulations. Morrison ass es ses aspects of bird population numbers as in dicators of environmental change, and Temple outlines current research on endangered species. The broad spectrum of reproductive ecology of birds is variously treated in this volume. Jehl and Murray explore sexual selection and some of the resulting complexities in the evolution of sexual size di morphism, primarily in shorebirds. Lawton and Lawton are concerned with the relationships between social behavior and breeding systems in which variation is found in the age at which reproduction is first undertaken. Oring examines the wide-ranging variation in polyandrous breeding systems in birds, while Rohwer is concerned with adoption versus infanticide in birds, and their relationships to reproductive fit ness.

All relevant ecological aspects of plankton, especially seasonal changes in the species composition, the role of competition for limiting resources in species replacements, the role of parasitism, predation and competition in seasonal succession are treated in detail considering phytoplankton, zooplankton and bacteroplankton. In addition to its use as a valid reference book for plankton ecology, this monograph may well be used as a model for other kinds of ecological communities.

The meeting on "Microbial Surface Components and Toxins in Relation to Pathogenesis" was held on May 15-19, 1989, in the Mitzpe Rachel guesthouse of Kibbutz Ramat Rachel in Israel. Four major topics formed the basis for the meeting: adhesion and colonization; cell invasion and intracellular multipli cation; evasion of host defenses; toxins and systemic effects. The presentations clearly show that our understanding of the pathology, pathogenesis and bacteria-host cell inter-action has greatly advanced over the last few years. The contributions to our knowledge on the biogenesis of adhesins and their molecular organization, as well as on the mechanism of adherence to infected target tissue by pathogenic bacteria, have been particularly impressive. significant progress has been made in defining the nature of pathogenic and cytotoxic factors produced by bacteria, and much has been learned about the biochemical and antigenic modifications occurring in diverse types of host cells upon infection. The discussions of poly saccharide capsules, bacterial endotoxins and secreted toxins illustrated the challenge and the possibilities for vaccine development."

The study of parasites and their interactions with hosts continues to represent a challenging area of modern biology. The availability of new techniques and instrumentation, coupled with the development of daring new hypotheses and concepts, has paved the way for the dramatic evolution of parasitology from a static descriptive endeavor to a dynamic one based on biochemistry, immunology, molecular biology, and modern cell biology. Studies of this nature obviously fall within the domain of pathobiology. Consequently, when the contributions included in this volume of Comparative PathobioZogy were offered to this series. after critical review, we welcomed the opportunity to make them available to the scientific community. The contributions included herein represent presentations delivered before enthusiastic audiences at three different symposia, all held in 1983. The first, entitled "Some Aspects of Modern Parasitology," was organized by Dr. Gary E. Rodrick of the University of South Florida and myself on behalf of the American Society of Zoologists. The chapters by C. E. Carter and B. M. Wickwire. B. J. Bogitsh, and W. M. Kemp were originally presented at that symposium. The second symposium. organized by Dr. G. Balouet of the Faculte de Medecine, Brest, France, and myself on behalf, of the Society for Invertebrate Pathology, was entitled "Cellular Reactions in Invertebrates." The chapters by G. Balouet and M. Poder and M. Brehelin were originally presented at this symposium.

The gastrointestinal tract is a complex anaerobic microbial ecosystem containing a vast assemblage of resident microorganisms performing a multitude of metabolic activities that play a key role in health and disease of humans and animals. Furthermore, the gastrointestinal microbes have a dominant impact on the growth and productivity of both ruminant and non-ruminant animals. This two-volume series on Gastrointestinal Microbiology reviews the literature and provides a comprehensive account of the biological significance of the microbiota present in the alimentary tract of a wide range of animals, in terms of their nutritional ecology, biochemical activities, development and composition, interactions and role in host health and disease. Recent developments in the areas of molecular ecology, bacterial genetics, immunological aspects of host microbe interactions at the level of the intestinal mucosa, bacterial translocation and intestinal disease are included. Although emphasis is placed on domestic ruminants and man, systems which have been extensively researched, this series also provides a full and integrated account of the nutritional ecology and microbial ecology in the gut of many diverse mammals, birds, fish, amphibians, reptiles and insects. This broad perspective allows more realistic interpretation, and better evaluation of, as well as greater insight into, the evolution, ecology, and function of the gastrointestinal ecosystem. These volumes contain contributions from a multidisciplinary group of internationally recognized authors, all active researchers in their particular fields.

After the publication of the Diagnostic Manual for the Identification of Insect Pathogens, the authors received many queries asking why they had not included the larger metazoan parasites as well as the microbial forms. An examination of the literature indicated that pictorial guides to the identification of nematodes and the immature stages of insect parasites were unavailable. Consequently we decided to rewrite the sections cover ing insect pathogens and combine these with new sections on ento mogenous nematodes and the immature stages of insect parasites. The result is the present laboratory guide, which is unique in covering all types of biotic agents which are found inside insects and cause them injury or disease. Included as parasites are insects and nematodes. Among the pathogens included are viruses, rickettsias, bacteria, fungi, and protozoans. Emphasis is placed on identification with an attempt to use the most easily recognizable characters. Use of a certain number of technical terms is unavoidable, and explanations of these can be found in most biological dictionaries or the glossary of invertebrate pathology prepared by Steinhaus and Martignoni (1970).

In 1980 a case of myxedema was treated in Lisbon by the implantation of a sheep thyroid gland with the immediate improvement in the patient s condition. A few years later, medications for the then ill-explained condition of the menopause included tablets made from cow ovaries. In the first quarter of the 20th century the identification vitamin D3 and its sunlight driven production in skin paved the way to the elimination of rickets as a major medical problem. Twenty years or so later Sir Vincent Wigglesworth established the endocrine basis of developmental moulting in insects, arguably the most commonly performed animal behaviour on Planet Earth. A paradigm that would unify these disparate observations arose between in 1985 and 1987 beginning with the identification of the glucocorticoid receptor and the nuclear receptor super-family. What follows is a timely and positive manifestation of the capacity, productivity and value of international human scientific endeavour. Based on intrigue, lively competition and cooperation a global effort has rapidly fostered a school of biology with widespread ramifications for the understanding of metazoan animals, the human condition and the state of the planet. This book is the first this century to try and capture the spirit of this endeavour, to depict where the field is now and to identify some of the challenges and opportunities for the future. "

Knowledge of cholesterol and its interaction with protein molecules is of fundamental importance in both animal and human biology. This book contains 22 chapters, dealing in depth with structural and functional aspects of the currently known and extremely diverse unrelated families of cholesterol-binding and cholesterol transport proteins. By drawing together this range of topics the Editor has attempted to correlate this broad field of study for the first time. Technical aspects are given considerable emphasis, particularly in relation cholesterol reporter molecules and to the isolation and study of membrane cholesterol- and sphingomyelin-rich "raft" domains. Cell biological, biochemical and clinical topics are included in this book, which serve to emphasize the acknowledged and important benefits to be gained from the study of cholesterol and cholesterol-binding proteins within the biomedical sciences and the involvement of cholesterol in several clinical disorders. It is hoped that by presenting this topic in this integrated manner that an appreciation of the fact that there is much more that needs to be taken into account, studied and understood than the widely discussed "bad and good cholesterol" associated, respectively, with the low- and high-density lipoproteins, LDL and HDL.

The juvenile hormones of insects are unique molecules in terms of their chemical nature (methyl esters of sesquiterpene epoxides) and action (both as modulators of morphogenesis during the larval life of insects and as a gonadotropic agent in many female adults). Although a symposium dedicated to the chemistry, metabolism and effects of juvenile hormone at a number of levels would be merited on the basis of its interest to the chemist, physiologist, endo crinologist, developmental biologist and entomologist, the juvenile hormones are special in the sense that juvenile hormone mimics (juvenoids, insect growth regulators, analogs) are currently being utilized to control various insec. t pests. Indeed, a number of commercial firms are currently developing new compounds with juven ile hormone activity that might possess a narrow spectrum of acti vity and which would be relatively biodegradable. Thus, a symposium on the juvenile hormones is also merited on a practical basis since juvenoids are already becoming constituents of our environment and it is apparent that in order to design effective mimics of the natural juvenile hormones, o e should understand the means by which juvenile hormone elicits its effects. As will become evident to the reader, the great majority of data presented at this symposium have not been published previously and the symposium itself was organized along natural divisions dealing with the chemistry, metaoolism and multi-level modes of action of the juvenile hormones. Special lectures were presented by Professors C. M. Williams, B. W. O'Malley and W. S."

The original aim of this book was to cover different aspects of the tradi tionally "filamentous" potex-, carla-, poty-, clostero-, and capilloviruses. The title The Filamentous Plant Viruses seemed the only suitable one, but it has led us to discuss also the quite different filamentous viruses of the rice stripe group-recently officially named the tenuivirus group which otherwise, indeed, might not have been conveniently covered in any volume of this series. The question must be asked: What is there new that justifies the presentation of a book of this kind? An outline of the answer may be Among the traditional filamentous viruses, much pro given as follows. gress has been made in elucidating the physical structure of potexvirus particles, and this work serves as an excellent model for discussion of and future experiments on the poty-, carla-, clostero-, and capilloviruses, which have comparable structures, although they are more difficult to manipulate. Work on the structure and strategy of the genomes of poty viruses is, however, relatively advanced and at a very interesting stage. The helper component that assists the aphid transmission of potyviruses has also recently received considerable attention, although the more we know about that, the less seems clear about the aphid transmission of the carlaviruses and closteroviruses, which apparently neither possess nor require a helper component."

The last decade has seen tremendous progress in our knowledge of the pollen development and gene expression on one hand and the characterization of pollen specific proteins on the other. In compiling the chapters for this volume, we have pragmatically categorized these basic developments in pollen molecular biology and biotechnology into two sections based on their applications in agricul ture and implications in medicine. Pollen developmental biology and gene expression: applications in agricul ture. Pollen development is an extremely complex process encompassing a series of biochemical, physiological and genetic events. At the basic level, sporophyt ically expressed genes may expound our knowledge of unique processes of cellular differentiation which ultimately give rise to a full-fledged organism. At the applied level, the studies on the pollen and male sporophyte-specific gene expression, and of promoters and transcription factors of relevant genes have the potential to manipulate the fertility in certain cash crops leading to agricultural biotechnology."

This book is a collection of papers describing some of the first attempts to apply the techniques of recombinant DNA and molecular biology to studies of the nervous system. We believe this is an important new direction for brain research that will eventually lead to insights not pos sible with more traditional approaches. At first glance, the marriage of molecular biology to brain research seems an unlikely one because of the tremendous disparity in the histories of these two disciplines and the problems they face. Molecular biology is by nature a reductionist approach to biology. Molecular biologists have always tried to attack central questions in the most direct approach possible, usually in the most simple system available: a bacterium or a bacterial virus. Important experiments can usually be repeated quickly and cheaply, in many cases by the latest group of graduate students entering the field. The success of molecular biology has been so profound because the result of each important experiment has made the next critical question obvious, and usually answerable, in short order. Studies of the nervous system have a very different history. First, the human brain is what really interests us and it is the most complex structure that we know in biology. The central question is clear: How do we carry out higher functions such as learning and thinking? How ever, at present there is no widely accepted and testable theory of learn ing and no clear path to such a theory."

This book is devoted to one of the central problems of contemporary thinking, for which c.P. Snow in 1959 coined the phrase of the "Two Cultures". In this concept, human endeavour is directed on one side to the (forward-looking) sci ences (mathematics, physics, chemistry, biology, etc.) and on the other side to the (backward-looking) humanities (including psychology, linguistics, sociology, etc.). In this dichotomy Snow saw no possibility of unification. On the other hand the urge towards self-consistency and harmony in the mental and spiritual lives of both man and society as a whole is clearly one of the major forces of creativity, both scientific and artistic. This force aims at the unification of the "Two Cultures" in order to build an integrated self-consistent system for our intellectual life. Some attempts in this direction have been made before, and will be described in this book. It is our aim to contribute to the achievement of an integrated mental life on the basis of information theory. In order to construct our model, we examine the laws of information theory, leading us to the deduction of the main laws inherent in both "cultures". Thus, we consider the evolution of both non-living and living matter, human behaviour, the phenomenon of language, the sphere of aesthetics, etc. We hope that our work will be useful both for researchers (who are trying to derive different integral theories) and for various other "consumers" of scientific knowledge (meaning broad circles of intellectuals).