The term 'dispersal centre' literally refers to the place from which a dispersal process started. However, it also implies the location of a centre of diversity, frequently even a recent one, as well as the location of a preservation centre or refuge during regressive phases in less remoted periods of earth's history, and that of a possible speciation centre. The latter may have been the place of differentia tion of subspecies, or species, provided that the isolation period has been suffi ciently long. The term deliberately brings the dynamics to prominence which is inherent in the process of dispersal. This dynamics is neither properly recognized when considering ranges 'whose recent structures more or less force us to consider them, as static entities' (DE LATTIN 1967, p. 16)*, nor adequately taken into account by systematic typology. Yet, it is, in fact, the change that takes place in a range, which is of great significance in evolutionary genetics. In the case of range regressions which may lead to a diminution or rupture of the range pattern according to the pressure of the endogenous or exogenous triggering factors, subsequently arising distribution obstacles may result in a geographical isolation of partial populations or popula tion parts. Their sufficiently long spatial and reproductive isolation and the allele loss resulting from the change of the population size promote a divergent develop ment."

GeoffGoldspink and I edited a book, Mechanics and Energetics of Animal Locomotion, which was published by Chapman and Hall in 1977. It dealt at an advanced level with all aspects of animal locomotion, emphasizing particularly the topics of then current research. Since then there have been more elementary books on the subject, including my own Locomotion of Animals (Blackie 1982), and specialized books on such topics as swimming and flight, but (despite very substantial progress in research) there has been no advanced book covering the whole range of animal locomotion. It seemed to me and to Professor Gilles (editor ofthis series) that a new book was needed. Plainly, a book of this length cannot contain everything that is known about animal locomotion. We have not attempted to make it encyclopedic, but have tried to show where the study of animal locomotion stands now, and where it is going. Older books remain useful as sources of long-established information.

El Nino is a meteorological and oceanographic phenomenon, which occurs at irregular intervals in the eastern tropical Pacific. Its most obvious characteristic is the warming of surface waters, which causes enormous disturbances of the marine environment. A severe Nino may also affect continental systems worldwide. This book gathers in a comprehensive way the information available on the effects of the exceptionally strong 1982-83 Nino on a group of marine mammals, the pinnipeds. It presents an analysis of the effects of environmental stress on the populations of top predators. Data and interpretations are based on a most unusual collection of long-term studies of pinniped population dynamics, behavior and ecology which spanned the El Nino event. The responses of pinniped populations to the El Nino disturbance of the marine ecosystem also has important implications for the management and conservation of marine mammal populations.

The invitation to contribute a volume to the series Studies in Brain Func tion offers me a welcome opportunity for a comprehensive presentation of my research on the eye movements of the rabbit, and for a review of the older results in the perspectives offered by the progress of my own work, but even more of the field in general. Characteristically this monograph em phasizes the views of the author, which may not always be generally accept ed. Although connections with the work by other investigators are discussed as much as possible, I have not attempted to be complete in reviewing all publications related to oculomotor function in the rabbit. While presenting an overview of current understanding of a system, it is always wise to trace the historical roots of our knowledge and concepts. On the one hand, we may find that many established concepts derive their strength more from convention and convenience than from rigorous evi dence. Such traditional ideas should be challenged by critical experiments, using the best available techniques. On the other hand, some of the older publications remain a source of inspiration, because they contain valid ideas which generate fruitful experiments even today. A remarkable example of this category is Ter Braak's work on optokinetic nystagmus, published in 1936."

This section will consider the structure and function of muscle receptors, as well as the central nervous system mechanisms with which they are concerned. In volume I of this Handbook, receptor mechanisms are discussed in detail. Also, the crustacean stretch receptor and the frog muscle spindle have been considered. The present section will be concerned with vertebrate muscle receptors with an emphasis on mammals. Muscle receptors provide interesting examples of specialized mechanorecep tors. The muscle spindle is a striking case of a receptor which is regulated in its function by the central nervous system in efferent neurons. Muscle receptors have long been known to playa crucial role in the reflex regulation of movement. In recent years it has become apparent that these receptors are also important in sensory phenomena such as the perception of position and movement. St. Louis, July 1974 c.c. HUNT Contents Chapter I The Morphology of Muscle Receptors. By D. BARKER. With 99 Figures . . . . . . . . . . . . . . . .. 1 Chapter II The Physiology of Muscle Receptors. By C.C. HUNT. With 21 Figures . . . . . . . . . . . . . . . . . 191 Chapter III Central Actions of Impulses in Muscle Afferent Fibres. By A. K. McINTYRE. With 8 Figures 235 Author Index 289 Subject Index 299 List of Contributors BARKER, David Department of Zoology, University of Durham, Science Laboratories, South Road, Durham DH1 3LE, Great Britain HUNT, Carlton C. Department of Physiology and Biophysics, Washington University, School of Medicine, 660 South Euclid Avenue, St. Louis, Mo. 63110, USA McINTYRE, A. K."

The majority of scientists interested in fertilization and early developmental processes will undoubtably have encountered the works of Alberto Monroy at some time in their careers. Alberto's contribution to this field spans oogenesis to embryogenesis, where he used physiological, biochemical and morphological tools to answer a number of basic problems in cell biology. This multi-disciplinary approach, together with his remarkable intellectual flexibility and humour has had an enormous impact on this field and all those fortunate enough to have worked with him. The chapters in this book have been divided into four sections. The initial presentations revolve around late events of gameteogenesis, that lead to a physiologically mature gamete. Probably the most exciting area for research at the moment is the identification of the cytoplasmic mechanisms responsible for the meiotic arrest of oocytes and the factors responsible for initiating their maturation (Chapters 3 and 4). Less is known about the physiological changes in the male gamete in preparation for fertilization and this may be identified as a major area for future research. Although comparable data for the plant kingdom is presently restricted to studies on marine algae, new techniques for isolating angiosperm gametes (Chapters 1 and 17) promise rapid advances in this field. The second section looks at the events and molecules involved in gamete recognition, binding and fusion. One of the most controversial topics is when does sperm-egg fusion actually occur (Chapter 14).

There can be little doubt that, to use the parlance of the advertising world, the elasmobranch fishes have a "high profile image" in today's world. To most mem bers of the general public they are seen as terrors of the deep, perfect aquatic predators, and the stars (or more acurately, the villains) of major Hollywood movie films and innumerable television nature programmes. Such an image belies the fact that the vast majority of elasmobranch species feed on invertebrates and that, for man, the threat from shark attack is infinitesimal compared with even being struck by lightning Similarly, there can be few biologists who have not carried out the classic vertebrate dissection of the dogfish at some stage early in the formative years of their scientific education. Yet elasmobranch species make up only a small proportion, perhaps little more than I %, of all vertebrates, and there are probably nearly 50 times as many teleost species as there are elasmobranchs. It is also curious that, as subjects for modern research, elasmobranchs seem to be chosen sometimes for their unique physiological characteristics and at other times because they represent excellent model systems for the study of some general process. Equally, it is for both these, seemingly contradictory, reasons that this book was proposed."

Summarizing research progress achieved in 32 areas of cell biology covered in this series, this volume places special emphasis on the following topics: recognition in parasitic and symbiotic systems - the molecular biology and genetics of susceptibility and resistance of plants and animals to pathogens, parasites and symbionts - the cell to cell recognition and differentiation - the most challenging problems in developmental biology of plants and animals - the plasticity in cell to cell communication which plays a major role in cell differentiation and function.

The 13th International Conference on Plant Growth Substances was held from the 17th to the 26th July, 1988 in Calgary, Alberta Canada under the auspices of the IPGSA (International Plant Growth Substances Association) and the University of Calgary. Over 550 participants from allover the world attended, along with 70 Associates and 25 University of Calgary graduate students who assisted in audiovisual presentations when not attending the scientific sessions. Fine weather prevailed, as was usual for summer on the eastern slopes of the Canadian Rockies, and participants arriving early visited the famous Calgary Stampede. A hosted buffet opened the Conference on Sunday evening. On Wednesday evening, following an afternoon field trip into the mountains of the Kananaskis Valley, the IPGSA traditional banquet became a western barbecue on Richards' Ghost River Ranch in the foothills of the Rockies, with folk and country and western music provided by the Great Western Orchestra. The fine Alberta weather continued through the weekend, and the Conference ended with a field trip to Sun shine Meadows, a World Heritage Site in Banff National Park.

The 1992 Chinese Peptide Symposium was held at Hangzhou, China on November 3--6, 1992 with 152 participants, including 46 from abroad, representing 10 countries. The three days conference was both intense and spiritually rewarding. The Biennial Chinese Peptide Symposium was aimed to provide a forum for advancing the exchange of knowledge, cooperation and friendship between the international and Chinese scientific communities. In order to exchange ideas and review the latest progress in depth, the scientific sessions were held at the mornings and evenings, while afternoons were devoted to social interaction and sightseeing of the unparalleled beauty of Westlake. For realizing the goal to catch up with a fast evolving and fascinating field, the Program Committee arranged eight sessions with 45 oral presentations and 72 posters on topics relating to peptide conformation, design, hormone and bioactive peptides, neuropeptides, recognition, synthesis and methodology in the Symposium and selected 94 articles for publication in this proceedings. As an organizer I was greatly encouraged by the active response of invited speakers and moved by enthusiastic cooperation and excellent contributions which led to the great success of the Symposium, since their presentations were of high quality and represented the latest advances in all aspects of peptide chemistry and peptide biology. Many authors concentrated their attention to a great challenge which peptide chemists have nowadays to face, i. e.

In July 1989 a symposium was held at the Physiology Department of the Georg August University, G6ttingen, on the physiological, biophysical, biochemical, and technical principles of the coding of chemical substances both in nervous systems and artificial devices. This book is the collection of the papers presented at that meeting. Biological and artificial systems for odor coding both have in common that the stimulus selectivity of the receptor cells (sensors) is usually very poor, and the mechanisms which determine selectivity and sensitivity are largely unknown. However, a poor selectivity allows the coding of an enormous number of stimuli by combinations of receptor activities. In the field of chemosensory information coding there are thus two major problems: the function of the receptors and the network that processes and evaluates the primary information of the sensors. Accordingly, this volume has three parts: sensors, the network following the sensors, and the coding in this network. The expert secretarial assistance of M. Holtmann in preparing the camera-ready manuscript is gratefully acknowledged. D. Schild G6ttingen, August 1989 CONTENTS l. Response of olfactory receptor cells, isolated and in situ, to low concentrations of odorants 1 Stephan Frings, Bernd Lindemann 2. Excitation and adaptation of frog olfactory receptor neurones upon stimulation with second messengers and natural odorants 9 D. Schild, J. A. DeSimone, S. Hellwig 3. Receptor selectivity and dimensionality of odours at the stage of the olfactory receptor cells 21 GiJJes Sicard 4.

The papers published in this Volume are the fruits of a symposium held in Regensburg in April 1987. The meeting was held to com memorate two most significant events in the development of com pound eye research. In chronological order these are firstly, Sigmund Exner's seminal monograph on the physiology of compound eyes of crustaceans and insects, which was first published in Vienna in 1891, and is now shortly to appear for the first time in the English translation Exner, S. (1989) The Physiology of the Compound Eyes of Insects and Crustaceans. Springer Berlin Heidelberg New York Tokyo]. Secondly, the meeting was also held in honour of Professor Hansjochem Autrum's 80th birthday. Professor Autrum, who is justly acknowledged as one of the pioneers of modern compound eye research, attended the meeting as the guest of honour. In keeping with these historical occasions, it has been our intention in this volume to present a comprehensive collection of short reviews covering the major aspects of compound eye research. Whilst the most up-to-date developments have been included in every field from optics, through photochemistry, phototransduction, integrative processes and behavior, an attempt has also been made to provide a historical perspective."

One hundred years after the birth of Anton Dohrn, his biography was compiled by Theodor Heuss, first president of the Federal Republic of Germany and a friend of the Dohrn family. Heuss not only conveys the family history of this great scientist, but also interweaves scientific and cultural history into his narrative. As a result a fascinating yet true story which provides insight into the cultural, political and scientific life in both Germany and Italy at the turn of the century has been created. "Anton Dohrn (1840-1909) was founder of the once world-famous zoological station at Naples, 'a permanent international congress of zoologists' ...written as a classic 'life and letters', "A" "Life for" "Science."..gives an excellent description of an interesting scientist in touch with the leading biologists of his time." (Arch. of Natural History)

Clonal forestry has come of age. Basic techniques in genetics and biotechnology of other organisms are generally applicable to forest trees. However, there are some differences, in particular in the juvenile- and maturation-related regeneration. Examined here are crucial topics of juvenility, maturation and rejuvenation in clonal propagation of trees. In addition, the genetics of clones, population biology of clonal deployment, propagation and field testing of clones, clone identification, clonal physiology, regeneration and variation in plant tissue cultures, the role of somatic embryogenesis in clonal forestry, and recent developments in biotechnology, including the molecular structure of trees and gene transfer are covered in depth.

The honeybee (Apis melli/era L. ) is one of the better studied organisms on this planet. There are plenty of books on the biology of the honeybee for all, the scientist, the beekeeper, and the layman. In view of this flood of publications one is tempted to ask: why does it require another one? The answer is simple: a new one is not required and we do not intend to present a new book on "the honeybee." This would really just add some more inches to the already overloaded bookshelf without sub stantial new information. Instead, we intend to present a book on the honeybee colony. This of course immediately releases the next question: so what is the difference? Although the difference may look insignificant at first glance, we try to guide the reader with a fundamentally different approach through the biology of honeybees and eusocial insect societies in general. The biology of individual colony members is only addressed when it is necessary to explain colonial mechanisms, and the colony as a whole, as a biological unit, which is the main focus of this treatise. Both of us felt that all current textbooks on bee biology put too much emphasis on the individual worker, queen or drone in the colony. Often it is com pletely neglected that the colony is a very significant (if not the most significant) biological structure in bee biology."

The major goal of 'Expanding Frontiers in Polypeptide and Protein Structural Research' has been to bring the various avenues for the exploration of protein structures to a single forum. The idea of organizing the symposiwn was conceived by one of the editors, V. Renugopalakrislman, during the 9th International Biophysics Congress satellite symposium at Kibbutz Nof-Ginosar, Israel in 1987. It was originally supposed to dwell on 2D NMR and molecular dynamics of polypeptides and proteins. During the earlier part of the last decade, these two approaches began to emerge as powerful tools to probe protein structures at the atomic level in solution. The developments in molecular biology ushered in the capability to design polypeptides and proteins for specific application in science and technology. The emergence of 2D NMR and molecular dynamics was greatly facilitated by contemporary developments in molecular biology and protein engineering. Therefore an international symposiwn devoted exclusively to 2D NMR and molecular dynamics studies of proteins was felt necessary to bring two major approaches in a single forum. In addition to emphasis on 2D NMR and molecular dynamics simulation, the scope of the symposiwn included optical spectroscopy, protein design, and new horizons in protein structure. The symposiwn consisted of five plenary sessions devoted to NMR and optical spectroscopy as probes for protein structure, protein dynamics, computational methods in protein design, and new horizons in protein structure. In addition, five workshops in related areas, viz.

No matter what forests are used for, forest managers have to deal with interactions between individual trees and between trees and other forest organisms. To understand these interactions, long-term monitoring of spontaneous forest development is necessary. A complete monitoring system has been developed including a computer package for analysis of long-term observation of forest dynamics. The system's name, "SILVI-STAR," is an acronym of SILVIgenesis and Single-tree Three-dimensional Architecture. A method of nested plot data collection on forest architecture and plant species composition has been developed out for monitoring purposes.

The Amazon is a giant piece of "amphibian" land which is the result of complex geological and evolutionary processes. The number of living beings in such a land is difficult to estimate. The interactions between these organ isms and the environment are fascinating but barely understood. These features lured us to the Amazon in 1981. However, soon after, we realized that the dimensions of these interactions were overwhelming. This book is designed to review aspects of the physiology and biochemistry of fishes of the Amazon. The description of the pulsative nature of the environment and the distinct features of the ichthyofauna of the Amazon were central to the main goal. Nevertheless, any complete view is limited by the magnitude of the intraspecific variability coupled with the complex fluctuations of the environment. Thus, we have placed an emphasis on respiratory physiology and biochemistry. The reference list was made as complete as possible, particularly regarding special publications not readily available. We hope that this book is useful for comparative physiologists, tropical biologists, and the people interested in interactions between organ isms and their environment. We are grateful to many people who contributed to the making of this book. Our initial ideas were influenced by Drs. Arno Schwantes, Maria Lufza Schwantes, Jose Tundisi, Anna Emflia Vazzoler, and Naercio Menezes."

Behavioural Mechanisms of Food Selection examines animals belonging to diverse trophic groups, from carnivores, herbivores, micro-algal grazers, to filter-feeders and detritus-feeders. In the past Optimal Foraging Theory has been applied to all these groups, but in different ways and in disci plines that rarely overlap. Here concepts and developments hitherto scattered in the literature are drawn together. This uniquely broad synthesis captures the state of the art in the study of diet selection and prescribes new objectives in theoretical development and research.

The European Polarstern Study 1988/89 2 3 Gotthilf Hempel\ Jarl-Ove Stromberg and Victor Smetacek 1 Zentrum fUr Marine Tropen6kologie, Centre for Tropical Marine Ecology, Universitatsallee GW lIA, D-2800 Bremen 33, FRG 2 Kristineberg Marine Biological Station, Kristineberg 2130, S-45034 Fiskebackskil, Sweden 3 Alfred-Wegener-Institut fUr Polar- und Meeresforschung, Am Handelshafen 12, D-2850 Bremerhaven, FRG This volume of"Polar Biology" is the product of a new ap- Antarctic; experimental and field; shallow water and ocea- proach to promote international cooperation in polar ma- nic; open water and pack-ice. All this was considered to sti- rine ecology - the European Polarstern Study (EPOS). This mulate and implant new ideas, approaches and methods venture brougth together 131 scientists from 14 countries in into marine Antarctic research, which had tended to be- Western and Central Europe and South America who parti- come somewhat dissociated from the main stream of inter- cipated in a series of three cruises on the ice-breaking rese- national marine ecology. To give some examples: Finnish arch vessel "Polarstern" to the Weddell Sea, Antarctica, from microbiologists normally studying bacteria in the freshwa- early austral spring to late autumn of19 88/89. The articles in ter ice of the Bothnian Bay, together with Dutch planktolo- this volume represent some of the contributions presented gists who had worked in Indonesian waters, coorporated at the EPOS Symposium held in Bremerhaven, Germany, in with German marine glaciologists. Ajoint Swedish-N orwe- May 1991.

The intention of this book is to offer a comprehensive description and discussion of autonomic nerve function in the vertebrates from several points of view. Sections on anatomy, biochemistry of the transmitter substances and the structure, physiology and pharmacology of the different types of autonomic neurons have been included, together with chapters dealing with the autonomic nervous control of some organs and organ systems in the different vertebrate groups. Although knowledge in several of these areas is based primarily on studies of mammals, a certain emphasis has been placed on the autonomic nerve functions in the non-mammalian vertebrates to describe, from a comparative physiological point of view, the adaptations and possible "phylogenetic trends" in the development of the autonomic nerve functions in the vertebrates. It is very obvious that the literature created by the vigorous research activities within the fields of autonomic nervous anatomy, histochemistry, biochemistry, pharmacology and physiology is vast indeed, and not all aspects of the subject may have received fair treatment in the present volume. With an analogy from astronomy, it is hoped that the mass compressed into this book has reached the level of an energy-emitting neutron star, rather than the black hole which would be the result of compressing too large a mass.

Constructional morphology explains features of organisms from a constructional and functional point of view. By means of physical analysis it explains the operational aspects of organic structures - how they can perform the activities organisms are expected to fulfil in order to survive in their environment. Constructional morphology also explains options and constraints during the evolution determined by internal constructional needs, ontogenetic demands, inherited organizational preconditions and environmental clues.

In view of the increasing problems of waste disposal in the Netherlands, plans were made to pipeline the waste to the Ems-Dollard estuary. To evaluate the practicability a project was started with the aim to implement a simulation model of an estuary ecosystem. This model was based on the knowledge of the hydrology, geochemistry and biology of the Ems estuary. For this approach data of the abiotic and biotic environment were collected in studies of the Ems estuary and are presented in this report. With its comprehensive information of biological processes as food webs, biomass production and nutrient supply, as well as of sedimentological and flux parameters, this book can be considered as a general model of an estuary ecosystem.

The eye has fascinated scientists from the earliest days of biological in vestigation. The diversity of its parts and the precision of their interaction make it a favorite model system for a variety of developmental studies. The eye is a particularly valuable experimental system not only because its tissues provide examples of fundamental processes, but also because it is a prominent and easily accessible structure at very early embryonic ages. In order to provide an open forum for investigators working on all aspects of ocular development, a series of symposia on ocular and visual devel opment was initiated in 1973. A major objective of the symposia has been to foster communication between the basic research worker and the clinical community. It is our feeling that much can be learned on both sides from this interaction. The idea for an informal meeting allowing maximum ex change of ideas originated with Dr. Leon Candeub, who supplied the nec essary driving force that made the series a reality. Each symposium has concentrated on a different aspect of ocular development. Speakers have been selected to approach related topics from different perspectives."