There is no multicellular animal whose genetics is so well understood as Drosophila melanogaster. An increasing number of biologists have, therefore, turned to the fruitfly in pursuit of such diverse areas as the molecular biology of eukaryotic cells, development and neurobiology. Indeed there are signs that Dro sophila may soon become the most central organism in biqlogy for genetic analysis of complex problems. The papers in this collection were presented at a conference on Development and Behavior of Drosophila held at the Tata Insti tute of Fundamental Research from 19th to 22nd December, 1979. The volume reflects the commonly shared belief of the participants that Drosophila has as much to contribute to biology in the future as it has in the past. We hope it will be of interest not merely to Dro sophilists but to all biologists. We thank Chetan Premani, Anil Gupta, K.S. Krishnan, Veronica Rodrigues, Hemant Chikermane and K. Vijay Raghavan for help with recording and transcription of the proceedings and Vrinda Nabar and K.V. Hareesh for editorial assistance. We thank Samuel Richman, Thomas Schmidt-Glenewinkel and T.R. Venkatesh for their valuable assistance in proofreading the manuscripts, and we also thank Patricia Rank for her excellent effort in the preparation of the final manuscripts. The conference was supported by a grant from Sir Dorabji Tata Trust.

Developmental Neuropsychobiology is a compendium of papers that deals with developmental neuroscience and developmental psychology, as well as the broad range of approaches toward brain-behavior development. One paper reviews the embryonic mechanisms including the pattern formation that develops in a single fertilized egg, particularly focusing on limb innervation as a special case of pattern formation. Another paper discusses the regulation of nerve fiber elongation during embryogenesis. One author analyzes the pathways and changing connections in the nervous system of the insect: he shows that manipulating neural organization by grafting results in the ability of the transplanted sensory cells to find the proper central connections. Another paper reviews the sex differences in developmental plasticity of behavior and the brain. These differences point to the vulnerability of males during development to incidences of autism, dyslexia, or cerebral palsy compared to females. One paper also examines alternative perceptions of parent- offspring relationships. This collection can prove helpful for researchers, students, and academicians involved in the disciplines of biological or psychological sciences.

First multi-year cumulation covers six years: 1965-70.

Studies of simple and emerging systems have been undertaken to un derstand the processes by which a developing system unfolds, and to understand more completely the basis of the complexity of the fully formed structures. The nervous system has long been particularly in triguing for such studies, because of the early recognition of a multitude of distinctly differentiated states exhibited by nerve cells with different morphologies. Anatomical studies suggest that one liver cell may be very like another, but indicate that neurons come in a remarkable di versity of forms. This diversity at the anatomical level has parallels at the physiological and biochemical levels. It is becoming increasingly easy to characterize the different cellular phenotypes of neurons. The repeatability with which these phenotypes are expressed may account in part for the specificity and reliability with which neurons form con nections, and it has allowed precise description of the first appearance and further development of the differentiated characteristics of individ ual neurons from relatively undifferentiated precursor cells. This rep resents a major advance over our knowledge of development at the level of tissues, and makes it feasible to define and address questions about the underlying molecular mechanisms involved. Central to these advances has been the clear recognition that there is no single best preparation for the study of neuronal development. Furthermore, it has become evident that no single technique can tell us all we want to know.

Intraspecific communication involves the activation of chemoreceptors and subsequent activation of different central areas that coordinate the responses of the entire organism—ranging from behavioral modification to modulation of hormones release. Animals emit intraspecific chemical signals, often referred to as pheromones, to advertise their presence to members of the same species and to regulate interactions aimed at establishing and regulating social and reproductive bonds. In the last two decades, scientists have developed a greater understanding of the neural processing of these chemical signals. Neurobiology of Chemical Communication explores the role of the chemical senses in mediating intraspecific communication. Providing an up-to-date outline of the most recent advances in the field, it presents data from laboratory and wild species, ranging from invertebrates to vertebrates, from insects to humans. The book examines the structure, anatomy, electrophysiology, and molecular biology of pheromones. It discusses how chemical signals work on different mammalian and non-mammalian species and includes chapters on insects, Drosophila, honey bees, amphibians, mice, tigers, and cattle. It also explores the controversial topic of human pheromones. An essential reference for students and researchers in the field of pheromones, this is also an ideal resource for those working on behavioral phenotyping of animal models and persons interested in the biology/ecology of wild and domestic species.

'The mind unlearns with difficulty what has long been impressed upon it. ' Seneca Reductionism, is, without question, the most successful analytical approach available to the experimental scientist. With the advent of techniques for cloning and sequencing DNA, and the development of a variety of molecular probes for localizing macromolecules in cells and tissues, the biologist now has available the most powerful reductionist tools ever invented. The application of these new technologies has led to a veritable explosion of facts regarding the types and organization of nucleotide sequences present in the genomes of eukaryotes. These data offer a level of precision and predictability which is unparalleled in biology. Recombinant DNA techniques were initially developed to gather information about the structure and organization of the DNA sequences within a genome. The power and potential of these techniques, however, extend far beyond simple data collection of this kind. In an attempt to use the new technology as a basis for analyzing development and evolution, attention was first focused on the topic of gene regulation, an approach that had proven so successful in prokaryotes. It is now clear that this has not been an adequate approach. Lewin (1984) has quoted Brenner as stating 'at the beginning it was said that the answer to the understanding of development was going to come from a knowledge of the molecular mechanisms of gene control. I doubt whether anyone believes this any more.