How do hormones and growth factors regulate animal growth in the developing embryo and after injury? What processes at the molecular level determine the growth patterns of different tissues? In this diverse synthesis of recent research the regulation of growth in response to environmental and genetic stimuli is discussed at the level of the animal, tissues and cells. Contrasts are drawn between regulation in foetal and adult tissues, and in different tissues such as the CNS, bone and muscle. Functional chapters focus on the molecular links between mechanical tension and muscle growth, for example, while other chapters review the roles of specific molecules such as growth hormone. This state-of-the-art review will be of significant interest to graduate students and research scientists in the fields of animal growth, endocrinology and cell biology.

With the emergence of the new field of evolutionary developmental biology we are witnessing a renaissance of Darwin s insights 150 years after his Origin of Species. Thus far, the exciting findings from evo-devo have only been trickling into college courses and into the domain of non-specialists. With its focus on the human organism, Quirks of Human Anatomy opens the floodgates by stating the arguments of evo-devo in plain English, and by offering a cornucopia of interesting case studies and examples. Its didactic value is enhanced by 24 schematic diagrams that integrate a host of disparate observations, by its Socratic question-and-answer format, and by its unprecedented compilation of the literature. By framing the hows of development in terms of the whys of evolution, it lets readers probe the deepest questions of biology. Readers will find the book not only educational but also enjoyable, as it revels in the fun of scientific exploration.

This book has evolved by processes of selection and expansion from its predecessor, Practical Scanning Electron Microscopy (PSEM), published by Plenum Press in 1975. The interaction of the authors with students at the Short Course on Scanning Electron Microscopy and X-Ray Microanalysis held annually at Lehigh University has helped greatly in developing this textbook. The material has been chosen to provide a student with a general introduction to the techniques of scanning electron microscopy and x-ray microanalysis suitable for application in such fields as biology, geology, solid state physics, and materials science. Following the format of PSEM, this book gives the student a basic knowledge of (1) the user-controlled functions of the electron optics of the scanning electron microscope and electron microprobe, (2) the characteristics of electron-beam-sample inter actions, (3) image formation and interpretation, (4) x-ray spectrometry, and (5) quantitative x-ray microanalysis. Each of these topics has been updated and in most cases expanded over the material presented in PSEM in order to give the reader sufficient coverage to understand these topics and apply the information in the laboratory. Throughout the text, we have attempted to emphasize practical aspects of the techniques, describing those instru ment parameters which the microscopist can and must manipulate to obtain optimum information from the specimen. Certain areas in particular have been expanded in response to their increasing importance in the SEM field. Thus energy-dispersive x-ray spectrometry, which has undergone a tremendous surge in growth, is treated in substantial detail.

Following on from the success of his two previous books, Remarkable Mathematicians and Remarkable Physicists, Ioan James now profiles 38 remarkable biologists from the last 400 years. The emphasis is on their varied life-stories, not on the details of their achievements, but when read in sequence their biographies, which are organised chronologically, convey in human terms something of the way in which biology has developed over the years. Scientific and biological detail is kept to a minimum, inviting any reader interested in biology to follow this easy path through the subject s modern development.

Many complex molecular interactions are involved in the development of the mammalian brain. Molecules serving as guidance cues for migratory cells, growing axons and for recognition of postsynaptic targets are a major topic for research because they are directly involved in the formation of neuronal circuits, thus creating the foundation for subsequent functional refinement through interactions with the environment. In addition, most guidance cue molecules are also involved in plasticity, damage repair and regeneration in the adult brain.

This volume reviews current knowledge on major classes of molecules involved in: guidance of growing axons; tau proteins involved in the establishment of axonal polarity, outgrowth and contact recognition; gangliosides and lectins involved in neuronal migration, neurite outgrowth and contact recognition; and myelin molecules that inhibit nerve regeneration.

The World Congress of In Vitro Fertilization and Alternate Assisted Reproduction, held in Jerusalem, Israel, 2-7 April, 1989, was the sixth in the sequence of these Congresses, but was the first to emphasize the major importance and the place of assisted reproductive technologies in the treatment of infertility. The eternal City of Jerusalem witnessed the gathering of more than 1500 participants from allover the world who shared and exchanged knowledge and up-to-date experience in this ever-evolving field. The high quality scientific contributions to the Congress culminated in the publication of this Proceedings. It embraces all-important aspects in the field of in vitro fertilization and alternate assisted reproduction. Papers on controversies and diversities of methods to stimulate the ovaries, imaging techniques, basic research and state-of-the-art papers on ovarian physiology, the role of GnRH and its analog, clinical aspects of IVF treatment and cryopreservation, up-to-date techniques in assisted reproductive technologies that are quickly developing in conjunction with IVF, were included. When should IVF be preferable to surgery? What are the ex pected up-to-date world results and what are the psychological, moral, ethical and religious implications? These are all the concerns of the treating team and are addressed here. Male factor infertility remains a frustrating problem, but advances in the understanding of sperm-egg interaction, sperm evaluation and preparation are reported. Micromanipulation emerges as a possible alternative to bring some relief to this problem, but it also promises to be central in promoting the field of prenatal genetic analysis."

Early embryonic loss is a continuing social and economic global problem. In human populations the estimates of interruptions early in pregnancy range from 35-60%. In animal husbandry (swine, ruminants) fully 30% of pregnancies fail to survive early events of gestation. The futility associated with this persistant high risk is even more unsettling because of advances made in assisted reproductive technology which, although this very selective methodology has added to our knowledge of embryo-endometrial interactions, has resulted in a birth rate of only 14%. These studies have instigated comparisons of the live relative contributions of the embryo and the uterus to the outcome of pregnancy. These analyses have shown that we have learned significantly less about the role of the uterus in deciding the outcome of either natural or assisted pregnancies. In 1979 a quotation by George Corner was used to set the tone of a meeting that was devoted to discussion of the cellular and molecular aspects of implantation. In spite of the proliferation in research activity which occurred in the following 15 years our real understanding of the embryo transfer process has fallen short of our expectations. We use the Corner quotation, once again, to preface this symposium so that we may recall that the fundamental nature of the process which regulates embryo-endometrial interactions still escapes us.

The auditory system has a remarkable ability to adjust to an ever-changing environment. The six review chapters that comprise Plasticity of the Central Auditory System cover a spectrum of issues concerning this ability to adapt, defined by the widely applicable term "plasticity." With chapters focusing on the development of the cochlear nucleus, the mammalian superior olivary complex, plasticity in binaural hearing, plasticity in the auditory cortex, neural plasticity in bird songs, and plasticity in the insect auditory system, this volume represents much of the most current research in this field. The volume is thorough enough to stand alone, but is closely related a previous SHAR volume, Development of the Auditory System (Volume 9) by Rubel, Popper, and Fay. The book fully addresses the difficulties, challenges, and complexities of this topic as it applies to the auditory development of a wide variety of species.

Each new volume of this publication brings the privilege of expressing some of my thoughts on subjects of interest to its readers. In the past year or so public concern about environmental and societal dangers has largely turned to those of cosmic proportion-Chernobyl, the thinning ozone layer, AIDS, and the like-and thankfully our subject matter has been allowed a respite. Even the miniepidemic of craniofacial and other malformations caused by the retinoid antiacne drug Accutane made no headlines. Incidentally, this might have been a tragedy of far greater proportions had it not been nipped in the bud by the historical ground work that quickly permitted it to be recognized as due to an environ mental teratogen-the sort of fact the public and authorities inadequately appreciate. But there is a warning connected with this abeyance of media focus on teratological matters. Disquiet over cosmic imbalances will sub side as they are corrected or horrendous projections fail to materialize, and even cures for dread infectious diseases, or Puritan revolution in terdicting such plagues, will be forthcoming, and these things will occur long before congenital malformations are no more. And as the year-in and year-out recurrence of over 100,000 an nual births of seriously malformed infants in the United States alone continues to force itself on the public consciousness, we can expect a heightened demand that "a cure" be found, because "if we can land a man on the moon, if we can prevent polio, why can't we . . ."

Why Efforts to Expand the Meaning of "Teratogen" Are Unacceptable Disagreement about nomenclature in teratology is not new. Dissent even about the very fabric of the discipline-what congenital malformations consist of-has often been voiced. Time, instead of resolving such diffi culties, has sometimes worsened them. For example, in the past it was agreed that congenital malforma tions are abnormalities of structure present at birth, but differences of opinion concerning where the line between normal and abnormal was to be drawn prevailed. It was obvious that, in order to discover the causes of congenital malformations and cast strategies for their prevention, it would be necessary to have knowledge of the baseline of their frequency, and that this required uniformity of definition of terms. Since malfor mations of primary social concern are those having grave outcomes (and are, paradoxically, also the commonest ones), it is logical that such condi tions were the first consideration of investigators and were the defects whose frequency was considered to comprise the required baseline.

In the last decade, since the publication of the first edition of Scanning Electron Microscopy and X-ray Microanalysis, there has been a great expansion in the capabilities of the basic SEM and EPMA. High resolution imaging has been developed with the aid of an extensive range of field emission gun (FEG) microscopes. The magnification ranges of these instruments now overlap those of the transmission electron microscope. Low-voltage microscopy using the FEG now allows for the observation of noncoated samples. In addition, advances in the develop ment of x-ray wavelength and energy dispersive spectrometers allow for the measurement of low-energy x-rays, particularly from the light elements (B, C, N, 0). In the area of x-ray microanalysis, great advances have been made, particularly with the "phi rho z" Ij)(pz)] technique for solid samples, and with other quantitation methods for thin films, particles, rough surfaces, and the light elements. In addition, x-ray imaging has advanced from the conventional technique of "dot mapping" to the method of quantitative compositional imaging. Beyond this, new software has allowed the development of much more meaningful displays for both imaging and quantitative analysis results and the capability for integrating the data to obtain specific information such as precipitate size, chemical analysis in designated areas or along specific directions, and local chemical inhomogeneities."

"The old order changeth, yielding place to new. " When Tennyson wrote this, he was unfamiliar with the pace of modem science else he would have said the new is displaced by the newer. When Gilbert and I gathered the papers for the first edition of this overview of metamorphosis, we aimed to provide a broad basis upon which the experimental analysis of the developmental changes called metamorphosis could proceed. We were both aware then that with the new techniques of biochemistry and with the revolutionary breakthrough to the nature of the gene, countless new possibilities were being opened for the exploration of the molecular basis of development. The resources offered by metamorphic changes offered unique opportunities to trace the path from gene to phenotype. Our expectations were high. I visited Larry Gilbert and Earl Frieden in their laboratories and saw with envy how far advanced they were then in the use of molecular methods of analysis. I had started on a different approach to develop an in vitro test for thyroid action on amphibian tissue. But circumstances limited my own progress to the initial delim itation of the technical possibilities of the in vitro system. Only from the sidelines could I watch the steady if slow progress of biology in penetrating the maze of molecular events by which animal tissues re spond to hormonal and other developmental factors."

Our understanding of the molecular mechanisms involved in mammalian brain development remains limited. However, the last few years have wit nessed a quantum leap in our knowledge, due to technological improve ments, particularly in molecular genetics. Despite this progress, the available body of data remains mostly phenomenological and reveals very little about the grammar that organizes the molecular dictionary to articulate a pheno type. Nevertheless, the recent progress in genetics will allow us to contem plate, for the first time, the integration of observation into a coherent view of brain development. Clearly, this may be a major challenge for the next century, and arguably is the most important task of contemporary develop mental biology. The purpose of the present book is to provide an overview that syn thesizes up-to-date information on selected aspects of mouse brain devel opment. Given the format, it was not possible to cover all aspects of brain development, and many important subjects are missing. The selected themes are, to a certain extent, subjective and reflect the interests of the contributing authors. Examples of major themes that are not covered are peripheral nervous system development, including myelination, the development of the hippocampus and several other CNS structures, as well as the developmental function of some important morphoregulatory molecules."

Developmental biology took shape between 1880 and the 1920s Basic concepts like the developmental role of chromosomes and the germ plasm (today's genome), self differentiation, embryonic regulation and induction, gradients and organizers hail from that period; indeed, the discipline was defined as a whole by the programmatic writings of Wilhelm Roux as early as 1889. The present essays cover the period up to the Nobel prize-winning work of Hans Spemann and Hilde Mangold. They were originally published in Roux's Archives of Developmental Biology, from Vol. 200 onward to the journal's centennial issues in 1995/96. The essays aim at introducing current adepts of developmental biology to observations and experiments that have lead their predecessors towards basic concepts still influential today.

Life As we Know It covers several aspects of Life, ranging from the prebiotic level, origin of life, evolution of prokaryotes to eukaryotes and finally to various affairs of human beings. Although Life is hard to define, one can characterize it and describe its features. The information presented here on the various phenomena of Life were all written by highly qualified authors including scientists, a professional athlete and three Nobel Laureates.

The overall scope of this new series will be to evolve an understanding of the genetic basis of (1) how early mesoderm commits to cells of a heart lineage that progressively and irreversibly assemble into a segmented, primary heart tube that can be remodeled into a four-chambered organ, and (2) how blood vessels are derived and assembled both in the heart and in the body. Our central aim is to establish a four-dimensional, spatiotemporal foundation for the heart and blood vessels that can be genetically dissected for function and mechanism. Since Robert DeHaan's seminal chapter "Morphogenesis of the Vertebrate Heart" pub lished in Organogenesis (Holt Reinhart & Winston, NY) in 1965, there have been surprisingly few books devoted to the subject of cardiovascular morphogenesis, despite the enormous growth of interest that occurred nationally and internationally. Most writings on the subject have been schol arly compilations of the proceedings of major national or international symposia or multiauthored volumes, often without a specific theme. What is missing are the unifying concepts that can make sense out of a burgeoning database of facts. The Editorial Board of this new series believes the time has come for a book series dedicated to cardiovascular morphogenesis that will serve not only as an important archival and didactic reference source for those who have recently come into the field but also as a guide to the evolution of a field that is clearly coming of age."

No field of contemporary biomedical science has been more revolutionized by the techniques of molecular biology than developmental biology. This is an outstanding concise introduction to developmental biology that takes a contemporary approach to describing the complex process that transforms an egg into an adult organism. The book features exceptionally clear two-color illustrations, and is designed for use in both undergraduate and graduate level courses. The book is especially noteworthy for its treatment of development in model organisms, whose contributions to developmental biology were recognized in the 1995 Nobel Prize for physiology and medicine.

It is appropriate at the outset of this book to pose a question that was often asked --of the organizers before the meeting took place and later among those who participated in the meeting -- "What is meant by 'Systems Approaches' in the study of developmental neurobiology?" The answer, as we originally conceived it, can be succinctly summarized by the word "interactions". That brief epithet was expanded during the general discussion portion of the meeting, where the following definition was offered: "Systems approaches in developmental neurobiology are unified by attention to the emergent properties of the developing system under investigation and by a focus on the aspects of development of the nervous system that depend on interactions among its various elements, be they molecular, intracellular or multicellular. " As opposed to ignoring complexity or trying to wish it away, those of us who utilize a systems approach embrace the principle that complexity is what makes the nervous system special. We have come to recognize that wherever we look, we find interactions which are to be probed and eventually. understood. Even the so-called "simple systems", a term that has been used to describe many invertebrate preparations, are embraced under the above definition, since with further study it is becoming increasing clear that such systems are not as simple as once thought. We also include molecular genetics under the systems rubric. After all, genes regulate other genes which regulate others, and so it goes.

One of the most impressive advances in the field of neuroscience over the last decade has been the accumulation of data on plasticity and regeneration in the nervous system of mammals. The book represents the contribution of a qroup of neuroscientists to this rapidly expanding field, through a Conference organized by the Institute of Developmental Neuroscience and Aging (IDNA). The meeting was held in Torino, Italy during April 1990 in honor of a great pioneer in the field of Neuroembryology, Professor Guido Filogamo. His introduction of the concept of neuroplasticity has had a significant impact on the study of neurobiology. This volume is divided into six sections, each focusing on one of the subject areas covered during the meeting Molecular and Cellular Aspects of Central and Peripheral Nervous System Development; Hormones,* Growth Factors, Heurotransmi tters, Xenobiotics and Development; In Vivo and in Vitro models of Development; Development and Regulation of Glia; Regeneration; and Aging.

Developmental biology has been transformed recently by discoveries in the fields of molecular biology, cell biology, and immunology. New ways of manip ulating mammalian development are uncovering control mechanisms and ena bling us to apply them in solving practical problems in animal production and human health. This book outlines some of these new manipulations and how they have contributed to the present state of developmental biology. Chapter 1 describes gene transfer by micro injection of cloned recombinant DNA into zygotes. Although the factors that affect transformation frequencies and integration sites are still unknown, such techniques offer a number of exciting prospects. Research models for human disease coula be artificially created and desirable characteristics in agricultural animals could be - hanced. . The theme of cell-to-cell transfer is continued in Chapters 2 and 3. Chapter 2 describes pronuclear transplantation by Sendai virus-induced fusion of the karyoplast with the enucleated embryo. Using this procedure, it has been dem onstrated that both male and female genomes are essential for normal develop ment, although the reason for this is not yet understood. Chapter 3 describes studies on the fusion of whole oocytes. ."

The NATO Advanced Study Institute on "Experimental Embryology in Aquatic Plant and Animal Organisms" was attended by more than 70 participants, including 15 invited main lecturers from 18 different countries. In accordance with the main purpose of the meeting, senior scientists, postdoctoral investigators and graduate students working in areas of descriptive and experimental embryology, classical, molecular and developmental biology, physiology and biochemistry etc. , were brought together for two weeks as a community with a strong common interest in "development"; that is, the multiple phenomena and mechanisms, in molecular, cellular, genetic and organismic terms, observed in the development of aquatic organisms. Initial concern that the great variety of biological models as well as of research subjects would harm the scientific quality and coherency of the course was unnecessary. It was exactly this breadth which made the Institute worthwhile for each of the participants. Since many of the "students" were younger scientists starting a career, it was the main goal of the course to offer a concise overview of selected system models of primarily aquatic organisms and to present and discuss research carried out in the past and in progress. Thus, each main speaker gave two in-depth lectures: one in which he presented an overview of "his" model and another dealing with current investigations.

The final volume in this significant series, this publication mirrors the broad scientific attention given to ideas and issues associated with the life-span perspective: constancy and change in human development; opportunities for and constraints on plasticity in structure and function across life; the potential for intervention across the entire life course (and thus for the creation of an applied developmental science); individual differences (diversity) in life paths, in contexts (or the ecology) of human development, and in changing relations between people and contexts; interconnections and discontinuities across age levels and developmental periods; and the importance of integrating biological, psychological, social, cultural, and historical levels of organization in order to understand human development.

The primary goal of this volume is to advance the conceptual unification of primatology and the other evolutionary sciences by addressing the evolution of behavioral flexibility in the Primate Order. One of the first lessons learned in introductory statistics is that events in the world vary. However, some species exhibit a greater range of phenotypic plasticity, including behavioral flexibility, than others. Primates are among those taxa advanced to display an uncommon degree of behavioral diversity. The proposed volume would explore the behavioral ecology and evolution of behavioral flexibility in primates in relation to the optimization of survival, (inclusive) reproductive success, and phenotypic influence.

Behavioral Flexibility in Primates: Causes and Consequences proposes that genetic conflicts of interest are ubiquitous in primates who may employ force, coercion, persuasion, persistence, scrambles, cooperation, exploitation, manipulation, social parasitism, dispersal or spite to resolve or manage them. Where one individual or group imposes severe costs to inclusive fitness or to the phenotype upon another individual, the latter may adopt a counterstrategy in an attempt to minimize its own costs. Counterstrategies may, in turn, impose costs upon the original actor(s), and so on, possibly yielding an evolutionary "chase" ("interlocus contest evolution"). The evolution of phenotypic plasticity in primates may often pertain to attempts to mitigate genetic conflicts of interest, and classic work in behavioral ecology leads to the conclusion that for females ("energy-maximizers"), conflict will pertain primarily to competition for food (that can be converted to offspring) while, for males ("time-minimizers"), conflict will pertain primarily to competition for mates. These related and novel perspectives are developed in this new volume.

1 Kevin Moses It is now 25 years since the study of the development of the compound eye in Drosophila really began with a classic paper (Ready et al. 1976). In 1864, August Weismann published a monograph on the development of Diptera and included some beautiful drawings of the developing imaginal discs (Weismann 1864). One of these is the first description of the third instar eye disc in which Weismann drew a vertical line separating a posterior domain that included a regular pattern of clustered cells from an anterior domain without such a pattern. Weismann suggested that these clusters were the precursors of the adult ommatidia and that the line marks the anterior edge of the eye. In his first suggestion he was absolutely correct - in his second he was wrong. The vertical line shown was not the anterior edge of the eye, but the anterior edge of a moving wave of patterning and cell type specification that 112 years later (1976) Ready, Hansen and Benzer would name the "morphogenetic furrow". While it is too late to hear from August Weismann, it is a particular pleasure to be able to include a chapter in this Volume from the first author of that 1976 paper: Don Ready! These past 25 years have seen an astonishing explosion in the study of the fly eye (see Fig.

For many, the terms aging, maturation and senescence are synonymous and used interchangeably, but they should not be. Whereas senescence represents an endogenously controlled degenerative programme leading to plant or organ death, genetiC aging encompasses a wide array of passive degenerative genetiC processes driven primarily by exogenous factors (Leopold, 1975). Aging is therefore considered a consequence of genetiC lesions that accumulate over time, but by themselves do not necessarily cause death. These lesions are probably made more severe by the increase in size and complexity in trees and their attendant physiology. Thus while the withering of flower petals following pollination can be considered senescence, the loss of viability of stored seeds more clearly represents aging (Norden, 1988). The very recent book "Senescence and Aging in Plants" does not discuss trees, the most dominant group of plants on the earth. Yet both angiospermic and gymnospermic trees also undergo the above phenomena but less is known about them. Do woody plants senesce or do they just age? What is phase change? Is this synonymous with maturation? While it is now becoming recognized that there is no programmed senescence in trees, senescence of their parts, even in gymnosperms (e. g. , needles of temperate conifers las t an average of 3. 5 years), is common; but aging is a readily acknowledged phenomenon. In theory, at least, in the absence of any programmed senescence trees should -live forever, but in practice they do not.