Cell biology is moving at breakneck speed, and many of the results from studies on insects have helped in understanding some of the central problems of biology. The time is therefore ripe to provide the scientific community with a series of up-to-date, well illustrated reviews of selected aspects of the sub microscopic cytology of insects. The topics we have included fall into four general groups: seven chapters deal with gametogenesis, four concern develop ing somatic cells, seventeen chapters describe specialized tissues and organs, and three chapters cover cells in pathological states. These accounts are illustrated with over 600 electron micrographs. The more than 1100 pages in the two volumes of Insect Ultrastructure combined labors of 49 dedicated contributors from II countries. represent the These authors have digested and critically summarized a very large body of information, and some measure of this effort can be gained from consulting the bibliographies that close each of the 31 chapters. These contain 2400 publica tions authored by 1500 different scientists. However, before we congratulate ourselves on the advanced state of our knowledge, it is worth remembering that representatives of less than 0.01 % of the known species of insects have been examined with the electron microscope.

This book will give an overview of insect ovaries, showing the diversities and the common traits in egg growth processes. The idea to write this book developed while looking at the flood of information which appeared in the early 1980s on early pattern formation in Drosophila embryos. At this time a significant breakthrough was made in studies of this little fly, combining molecular biological methods with classical and molecular genetics. The answers to questions about early pattern formation raised new questions about the architecture of ovaries and the growth of eggs within these ovaries. However, by concentrating only on Drosophila it is not possible to form an adequate picture of what is going on in insect ovaries, since the enormous diversity found among insects is not considered sufficiently. Almost forgotten, but the first to study the architecture of ovaries, was Alexander Brandt writing in 1878 in aber das Ei und seine Bildungsstaette (On the egg and its organ of development). More than 100 years later, a series of ten books or more would be required to survey all the serious informa tion we have today on insect oogenesis. Thus, this book is a personal selection and personal view on the theme, and the authors must be excused by all those scientists whose papers could not be included. The book briefly describes the ectodemes, i. e.

Fourteen years have passed since the publication of David Spencer Smith's Insect Cells: Their Structure and Function. Here the results of a decade of electronmicroscopic studies on insect cells were summarized in an organized and integrated fashion for the first time, and the ultrastructural characteristics of different specialized cells and tissues were abundantly illustrated in the 117 plates this monograph contained. In the intervening period great progress has been made in the field of Insect Ultrastructure. Organelles not even mentioned in Smith's book, such as synaptonemal complexes, clathrin baskets, fusomes, and retinular junc tions, have been identified and functions proposed for them. There have also been many technical advances that have profoundly influenced the direction of subsequent research. A spectacular example would be the development by Miller and Beatty of the chromosomal spreading technique which allowed for the first time ultrastructural studies on segments of chromosomes containing genes in various stages of replication and transcription. Then there is the freeze-fracture procedure first described by Moor and his colleagues. This technique permitted an analysis of intercellular junctions that was impossible with the conventional sectioning methods. The results greatly clarified our understanding of the channels for ion movement and the permeability barriers between cells and also the membrane changes that occur during the embryonic differentiation and metamorphosis of various types of insect cells.

Entomological research benefits from a great diversity of technical approaches - from the molecular to the descriptive - and these are applied to an even greater diversity of insect species. As a consequence, common themes and trends in entomological research can often be overlooked as each researcher focuses on his or her own area of interest. The purpose of this volume is to bring together diverse areas of research under one common theme. The book is divisible into four conceptual areas: the structural biology of the midgut; digestion and transport; the insect midgut as a target for control strategies; and the idgut as an environment for other organisms. Each chapter is written by scientists active in the reviewed research area and a truly international team of contributors has been chosen by the editors. Biology of the Insect Midgut will be of immense use to advanced undergraduate and postgraduate students, and researchers in entomology, physiology and pest control.

This new work contains the first integrated discussion of the role of olfaction in mosquito-host interactions. It covers the practical applications of this knowledge in attempting to control malaria as a problem for world health. The volume begins with a general overview of mosquito life cycle styles and how odour-mediated host location fits into the repertoire of behaviours that a specific species may exhibit. Certain aspects of insect olfaction and its underlying physiological mechanisms are incorporated within the book.

When established four years ago, the scope of this international series in electron microscopy essentially was to provide an opportunity for the pUblication of selected review contributions by specialists in ultrastructural research. Previous volumes presented over the last three years have focused on special topics of present interest in ~'ontemporary biomedicine such as endocrine cells, reproduction, and connective tissues. In these fielCls, in fact, integrated methods of electron microscopy have contributed much to generate new ideas and concepts of general value in both basic and clinical applications. The Ultrastructure of the Digestive Tract basically follows the same guidelines and style of the other books in the series and is an invited collection of selected contributions of authors from various laboratories active in the field of electron microscopy. Therefore, although the various chapters consist of individual topics, they nevertheless should be considered as interrelated contributions of specific subjects in the field. The idea was to have critical reviews of aspects previously published elsewhere by experts in the field who, as a rule, include other relevant information in their articles in order to update and enrich the subject. This book contains fifteen chapters by renowned electron microscopists. Each chapter, according to the policy of the editors, reviews a particular topic in great detail, providing updated information, study methods and results, authors' ideas on future investigative approaches, and possible guidelines for forthcoming work. We hope that this book will be useful to cell biologists, morphologists, physiologists, and pathologists.