Air pollutants provide environmental conditions that drastically differ in many respects from those to which forest trees are naturally adapted. Leading experts in the field here consider these questions of immediate relevance arising from the changing environment: (1) Do air pollutants introduce effects of selection that differ from those known for populations that are not subject to such stress conditions? (2) If air pollutants introduce quantitatively or even qualitatively novel selective effects, which consequences might arise from the adaptation of forest tree populations to the present conditions as well as for the preservation of adaptability to future conditions? In addition to these questions, concepts for preservation of genetic resources are discussed.

The time seems ripe for a critical compendium of that segment of the biological universe we call viruses. Virology, as a science, having passed only recently through its descriptive phase of naming and numbering, has probably reached that stage at which relatively few new-truly new-viruses will be discovered. Triggered by the intellectual probes and techniques of molecular biology, genetics, bio chemical cytology, and high resolution microscopy and spectroscopy, the field has experienced a genuine information explosion. Few serious attempts have been made to chronicle these events. This comprehensive series, which will comprise some 6000 pages in a total of 19 volumes, represents a commitment by a large group of active investigators to analyze, digest, and expostulate on the great mass of data relating to viruses, much of which is now amorphous and disjointed, and scattered throughout a wide literature. In this way, we hope to place the entire field in perspective, and to develop an invaluable reference and sourcebook for researchers and students at all levels. This series is designed as a continuum that can be entered any where, but which also provides a logical progression of developing facts and integrated concepts."

This book is the first comprehensive description of development of the Acipenserid fish published in the English language. It con tains the results of more than 40 years of studies by the authors and their colleagues. My own life in science has been intimately related both with the authors and the fish, which are the subject of this book. Therefore, it gives me a great pleasure to present to the English reader an expanded version of the book. Those interested in the history of biology must be well aware of the fact that genetics in the USSR was practically demolished by Lysenko at the session of the Lenin All-Union Academy of Agricultural Sciences in 1948. However, it is much less well known that other fundamental branches of biology were also persecuted at that time, experimental embryology (developmental mechanics) among them. As a result, many embryologists, in cluding the authors of this book, were forced to turn to more ap plied problems, this being the only way to continue research. They had to abandon amphibians and concentrate their efforts on sturgeon."

Since the Russian edition of this book was published in 1975 many new research works have appeared which have made necessary some additions for the English edition, to reflect progress in molecular developmental genetics. Recent important findings in this field have brought about essential corrections to the concept of genetic regulation of the process of cell differentiation. The discovery of the mosaic structure of a gene prompted the re evaluation of our considerations about the regulation of gene activity in eukaryotes, and the data about transcriptional events during ontogenesis are of great importance as well. Formerly it was generally accepted that a derepression of genes was responsible for cell differentiation in the process of develop ment. Recently three important conclusions have been derived (Davidson and Britten, 1979) which help to pose the problem in a new way: 1) Only a small part of single copy sequences of DNA is represented in nuclear RNA of a given type of cell or tissue: 10% to 20% in sea urchin embryos, 11 % in rat liver, 4% to 6% in Drosophila cell culture, etc. Since only about 10% of single copy sequences represent the structural genes (Davidson and Britten, 1973), transcription of almost the whole set of structural genes occurs."

By evolutionary adaptation to the perpetual day-night changes in envi- ronmental conditions, eukaryotic organisms have acquired an endogen- ous programme. This mechanism exhibits the characteristics of a self- sustaining oscillation the period of which approximates that of the earth's rotation. For animals such a property was first clearly demon- strated by Maynard S. Johnson (1939) who recorded, in constant conditions, free-running activity rhythms of white-footed mice (Peromyscus /eucopus). Johnson concluded from his observations that "this animal has an exceptionally substantial and durable self-winding and self-regulating clock, the mechanism of which remains to be worked out". Twenty years later, the formal properties of this "circadian" clock and its use by organisms as a time-keeping device were summa- rized at the Cold Spring Harbor Symposium in 1960 (Chovnick 1961). During the following two decades, investigations have turned towards an analysis of the physiological mechanisms involved in and the search for a central masterclock. These efforts led to the discovery that the pineal organ of submammalian vertebrates and the suprachiasmatic nuclei of birds and mammals are major candidates for a role as central circadian pacemakers. At the same time the neural pathways through which these structures are coupled to the light-dark cycle were identi- fied. Furthermore, it was established that the pineal gland and the suprachiasmatic nuclei are closely related structures that integrate the functions of circadian timekeeping and photoperiodic time measure- ment.

Communication is both a prerequisite and manifestation of social organization and in this sense several chapters of this volume are aimed to investigate the way vocal communication serves its ultimate function of maintaining social organization. Although manifold parallels exist to vocal communication in birds, additional mechanisms of vocalization are found in primates. Treating the various psychological, ecological, behavioral, and neurobiological aspects of vocalization this book provides an interdisciplinary approach for the understanding of biocommunication in primates including humans. Conceptual as well as methodological considerations are given in a balanced way. The addition of a comprehensive glossary gives an overview also to nonspecialists in this field.

The new field of applied genetic research, genetic toxicology and mutation research investigates the mutagenicity and cancerogenicity of chemicals and other agents. Permanent changes in genes and chromosomes, or genome mutations, can be induced by a plethora of agents, including ionizing and nonionizing radiations, chemicals, and viruses. Mutagenesis research has two aims: (1) to understand the molecular mechanisms leading to mutations, and (2) to prevent a thoughtless introduction of mutagenic agents into our environment. Both aspects, namely, basic and applied, will be treated in the new series Advances in Mutagenesis Research.

In 1954, when I obtained my B. Sc. (Honours School) degree in Zoology, I was asked by my advisor, the late Professor Vishwa Nath, to make comparative cytological studies of oogenesis in birds for my M. Sc. (Honours School) thesis submitted to the Panjab University in 1956. Using the classical techniques of cytology, I studied the various aspects of follicle growth and atresia in five species of birds. Professor Vishwa Nath, who himself devoted most of his life to the study of the comparative cytology of gametogenesis in animals, was so much impressed by my findings on avian oogenesis that he asked me to continue my research work for the Ph. D. degree under his supervision. During my research work on avian oogenesis, I became very much interested in further comparative study of ovarian follicles in vertebrates and thus decided to make comparative, morphological and histochemical studies of ovarian follicles in reptiles, birds and mammals. Actually, very little information was available in this regard in 1957 when I started working for the Ph. D. degree. In subsequent years, I and my numerous dedicated and highly motivated M. Sc. and Ph. D. students con tinued to make comparative, morphological, histochemical, biochemical and physiological studies of ovarian follicles in all groups of vertebrates. In connection with the subject of this book, I would like to make special mention of my two brilliant students, namely Dr. S. K. Varma and Dr. R. K."

Genetic engineering through DNA recombinants and the in vitro manipulation of isolated protoplasts has recently attracted much atten- tion in agricultural biotechnology, and has greatly advanced during the last 5 years. In an earlier book, Plant Protoplasts and Genetic Engineer- ing I, methods for the isolation, fusion and culture of protoplasts were reviewed and the regeneration of complete plants from isolated pro- toplasts of rice, potato, soybean, linseed, cabbage, chicory, lettuce, but- terbur, orchids, citrus and some other tree species, and interspecific and intergeneric somatic hybrids in Lycopersicon, Petunia, Nicotiana, Solanum, Glycine, Citrus, Brassica, Medicago and Trifolium spp. were discussed. The present volume, Plant Protoplasts and Genetic Engineering II, deals with some of the newer techniques such as microinjections, elec- trofusion, flow cytometry, uptake and integration of DNA, nuclei, iso- lated chromosomes by plant protoplasts and the subsequent regeneration of transgenic plants. The literature on the DNA recombinants and genetic transformation, both Agrobacterium-mediated and direct gene transfer in agricultural crops and trees, such as poplars, is reviewed, and the uses of cytoplasts and miniprotoplasts in genetic manipulation are highlighted.

The third Chinese Peptide Symposium, held in Beijing, China on June 13-17, 1994, attracted 156 delegates representing 11 countries. Nobel Laureate Professor Bruce R. Merrifield was among the 51 international participants, which included many other eminent peptide scientists. Our goal for CPS-94 was to provide a forum for the exchange of knowledge, cooperation and friendship between the international and Chinese scientific communities, and I believe this goal was met. The program consisted of 10 sessions, with 43 oral and 42 poster presentations. Topics included synthetic methods, molecular diversity and peptide library, design of neuroactive and other active peptides, conformation and protein modeling, peptide immunology and challenging problems in peptides. There were 75 articles selected for publication in these proceedings. CPS-94 was hosted by the Institute of Materia Medica, Chinese Academy of Medical Sciences and Beijing Medical University. Professor James Tam, Professor Meng-shen Cai and I were honored to serve as Vice-chairmen and Chairperson, respectively, as recommended by the Program Committee of the CPS-92. The enthusiastic cooperation and excellent contributions were gratifying, and the active response of the invited speakers guaranteed the success of the symposium. The presentations were of excellent caliber and represented the most current and significant aspects of peptide science.

Peritrophic membranes are secretion products of the midgut. For long they have been related only to insects, but they occur widely in the animal kingdom. They effect a part of the gut lumen and function not only as a mechanical protection barrier, but also as an ultrafilter, a barrier to parasites, and as envelopes for fecal pellets. Such peritrophic envelopes are of great ecological importance in marine environments. The book is divided into the following themes: - Occurrence - Formation and Structure - Degradation - Chemical Composition - Functions. It is the first comprehensive compilation of all data concerning peritrophic membranes and will provide a basis for future researches in this up to now often neglected field.

Parasitic Disease, second edition remains unique in its emphasis on depictions of complete life cycles and its skillful knitting of basic and clinical information. Superbly illustrated with black and white and color photomicrographs and halftone drawings, it is an ideal text for medical, graduate, and advanced undergraduate students of parasitology and an excellent reference for physicians and researchers.

Fish are extremely successful vertebrates. Because of a long and divergent history they are now found in almost every conceiv able aquatic habitat. This radiation has been accompanied by great diversity in structure, physiology, and behaviour. Despite this variability, fish must solve a number of basic problems that are common to all animals. The most important of these are: (1) to find and ingest appropriate food; (2) to avoid predation; and (3) to reproduce. The main purpose of this book is to describe the variety of behavioural strategies that fish use in coping with these problems. My approach has been to draw together material from both field and laboratory work that is widely scattered in the litera ture. The major emphasis is on field studies, since my main concern is with adaptive solutions to problems, and I believe these are most likely to be correctly perceived by workers who are familiar with the natural ecological setting of their animals. Of course, many details of behaviour cannot be seen and quantified adequately in the field, and therefore I have not ignored laboratory studies. However, even here I have concen trated on work that illustrates the variety of solutions that fish use to solve the three basic problems. Much important work, for instance on causation, development, and learning, is not included."

Bivalve filter-feeding mollusks are important components of coastal ecosystems because they remove large quantities of suspended material from the water and excrete abundant amounts of reactive nutrients. These animals are also major prey for numerous predators including birds, fish, mammals, and invertebrates; furthermore, they are significant food resources for humans. While studies on the organismic and population level have dominated bivalve ecology, the recent focus on the ecosystem roles of filter feeding systems has led to larger-scale investigations. With this approach the specific topics of physiology, grazing, predation, nutrient cycling, physical environment, computer simulation modeling, and environmental management are combined into a meaningful whole.

Volume 4 of the series "The Man in the Ice contains the newest results of the scientific research groups working on the Iceman during the last years. By means of different methods AMS-radiocarbon dating, bryology, dendrology, analysis of diatoms, macroremains and pollen the reader gets information about several aspects of the Iceman s lifestyle and environment as well as the vegetation and climate of the Otztal region. Investigations of the artefacts give insight into prehistoric craftsmenship. By several different approaches the potential location of his settlement is reconstructed. The good preservation of the pollen in his food residue allowed even a reconstruction of the season when the Iceman died. Willow leaves contained the information about the CO2 in the air the Iceman breathed. Detailed pollenanalyses of mire deposits in the alpine region of the Otztal gave insight into the genesis of the alpine grass heath and early pastoral farming of a time long before the Iceman lived. Radiocarbondating of organic matter from the Iceman s finding spot detected a piece of wood from the Early Neolithic that demonstrates the early interest of prehistoric people in these highland zones. These are only some of the new results in this book. A perspective of future research activities is given.

Understanding the brain mechanisms which underlie behavior is one of the most challenging tasks of modern biology. The study of these mechanisms can be approached using a variety of biological systems as models, depending essentially on the type of question being asked and the technical approach which is considered. In vertebrates, the study of brain neurochemistry in relation to behavior e, xpression has made tremendous progress during the last two decades. In particular, much at tention has been devoted to the effect of steroid hormones on brain structure and activity in connection with social and mainly reproductive behavior. This book exemplifies some of the major trends in the field. I did not attempt to cover exhaustively all the work that has been done in this area but rather to present a series of selected reviews on the molec ular and cellular brain mechanisms most directly related to social behavior. This selection obviously reflects my own interests but also, I believe, highlights those areas of research in which important progress has been made in recent years. A number of brain biochemical or cellular mechanisms which could be related to behavior, but have not been formally demonstrated to be so, are consequently ignored. The focus here is on social behavior and thus steroid-dependent processes are covered in priority. This choice of course leads us to ignore major trends in brain and behavior research but this is, I hope, clearly reflected in the title of the volume."

A compelling argument of how human health is adversely affected by our poor treatment of non-human animals. The author contents that in order to successfully confront the 21st Century's health challenges, we need to broaden the definition of the word 'public' in public health to include non-human animals.

In 1958 E. BUNNING published a book in the former series "Proto plasmatologia" entitled "Polaritat und inaquale Teilung des pflanzlichen Protoplasten" (polarity and unequal division of the plant protoplast) in which for the first time results of experimental plant cytomorphogenesis were re viewed. This book was based completely on light microscopic observations and rather simple experimental techniques. Since then our knowledge of basic cytomorphogenetic mechanisms has greatly increased, especially with the introduction of modern ultrastructural, biochemical and sophisticated experi mental methods so that the field of cytomorphogenesis in our days should be considered a separate discipline within the general field of cell biology. This book, "Cytomorphogenesis in Plants," represents a necessary attempt to bring together current knowledge in this field of research on a comparable basis. Unfortunately enormous gaps in our understanding of the underlying principles of cytomorphogenetic events still exist. Therefore it seemed reason able to present a book composed of individual chapters, each written by experts for a defined experimental system. Each chapter represent a separate treatise with its own references, hence it was not possible to avoid some overlap both in the text and in the literature of the chapters without destroying the uni formity of the respective article."

Anticlastogens in Mammalian and Human Cells covers research on the protection of chromosomes from the action of chemical mutagens by use of natural and synthetic antimutagens, which, because of their specific action on clastogenic damage are called anticlastogens. Based on an introductory chapter on nature and mode of formation of chromosome aberrations induced by chemical and also physical mutagens, the action of anticlastogens is discussed in detail. A definition and delineation of the term anticlastogenesis is followed by considerations on the various possibilities of classifying anticlastogens. Attention is paid to the action of anticlastogens in mammalian and human cell culture systems, in vivo data on anticlastogens are presented in great detail, as are the actions of anticlastogens on induced sister chromatid exchanges in various test systems. A mainly historical side-glance at the action of anticlastogens on chromosome damage induced by ionizing radiation is taken. The practical consequences of the findings on anticlastogenic action are extensively discussed as aspects of further research.

The diseases that fall under the generalized group of demyelinating diseases -Multiple Sclerosis, Leukodystrophyes, Encephalomyelitis-are the focus of worldwide concern. This volume contains papers presented by leading scientists who attended the NATO Advanced Research Workshop held at the Istituto Superiore di SanitA, Rome, March 1-4, 1993. This book is an update of the previous one published in 1987 of the research discussed at a similar meeting held in 1986. It was decided to hold this 2nd meeting since there has been great progress in the advances in understanding the myelinogenesis process in the last five years. The workshop gathered together scientists from many fields such as cellular and molecular biology, immunology, pathology, virology and of course clinical neurology. Stimulating ideas were exchanged in the hope that more knowledge of demyelinating diseases can lead to new theraupetic approaches. Although the workshop was on the whole similar to the previous one, this time there was more emphasis on experimental models and clinical aspects. In the former the use of animal and cellular models as tools for understanding the pathological mechanisms linked to human disease were discussed; in the latter the clinicians described the filtering down of basic research to clinical treatment The publication of this interdisciplinary exchange is to make known the results of the most recent research among the investigators from allover the world involved in these studies.

When Richard Goldschmidt' coined the term "intersexuality" in 1915, he intended it to apply to normally dioecious species which exhibit some kind of mixture between male and female characters. However, as knowledge of the bewildering variability present in the sexual orga nization of members of the animal kingdom has increased, the original meaning of the word has changed. Today many authors define inter sexuality as "the presence of both male and female characteristics, or of intermediate sexual characteristics, in a single individual."2 This more extensive and widely accepted concept justifies the title of our book . Among all the anatomical and physiological features of living organisms the reproductive system has a unique importance for the perpetuation of the species. Conversely, reproductive processes are of little or no account for the viability of the individual. Therefore, within the framework of general biology reproduction has all too often been looked at solely from the point of view of genetics. Lively discussions about genotypic versus phenotypic sex determination long dominated the sci entific literature on sexuality in animals; this one-sided emphasis has tended to obscure many important facets of an organism's ability to reproduce. Recent developments in current biological research have brought the classic problem of sex differentiation into focus again, and the rapid progress being made in comparative endocrinology has added a new di mension to the study of reproductive biology."

Attention to viral infections and pathology previously focussed on diseases of economically important fish. In recent years, however, much new information on molecular virology and oncogenicity derives from viruses occurring in amphibians. New insights into the field of zoonosis were gained by studies of lower vertebrates serving as intermediate hosts in multiple human infections. Certain viruses, e.g. the influenza virus or calicivirus, seem capable of bridging species lines and even the land - sea interface. Global developments in aquaculture are indicated in influenza pandemics. These proceedings present research findings on viruses of fish, amphibians and reptiles, including defence mechanisms, zoonoses, evolutionary considerations and diagnostic approaches.

Resulting from a Royal Society discussion meeting, this volume presents a short review of the topic of parasite-host co-evolution. Current thinking on evolution in parasites, viruses and other pathogens is discussed.

Studies of chemical recognition in biology were initiated about half a century ago with the flrst kinetic data obtained on enzyme catalysis and inhibition. They led to a rather static representation of the recognition process illustrated by the lock and key model that still continues to influence our overall image of recognition and its specificity. In several cases, crystallographic studies of enzyme-substrate complexes have supported this model. Indeed, in a crystallized ligand-enzyme complex, a close fltting is observed between the active center of the enzyme and the functional groups of the ligand. How ever, this does not necessarily result from a direct recognition process between rigid structures, but may result from a progressive adaptation during which the initial struc tures of the enzyme and the ligand are modified (induced-flt mechanism). Recently, a great deal of work has been devoted to the study of recognition in more complex systems such as the replication or the translation machin ries; clearly, the extraordinary precision of such systems cannot be explained solely in terms of physical matching between enzymes and their substrates. This has led to a noticeable change of perspective in these areas. As a result of the new kinetic viewpoint, one rather focuses on the time-course of the processes, on the kinetic balance between steps of the reaction, on the energy-accuracy relationships and on the strategies which permit the achievement of high precision using relatively error-prone components in an appropriate dynamic interplay."

Oceanic islands represent a set of systems in which biological diversity varies as a consequence of remoteness or size, not environment; they are also generally simpler than continental ecosystems. Islands therefore provide an opportunity to determine the direct effects of biological diversity on ecosystem function.
The volume addresses the components of biological diversity on islands and their patterns of variation; the modern threats to the maintenance of biological diversity on islands; the consequences of island biology and its modification by humanity regarding aspects of ecosystem function; the global implications of islands for conservation; and how islands can help one to understand the processes inducing changes throughout the world.