One of the major questions in the evolution of animals is the transition from unicellular to multicellular organization, which resulted in the emergence of Metazoa through a hypothetical Urmetazoa. The Comparative Embryology of Sponges contains abundant original and literary data on comparative embryology and morphology of the Porifera (Sponges), a group of 'lower Metazoa'. On the basis of this material, original typization of the development of Sponges is given and the problems concerning origin and evolution of Porifera and their ontogenesis are discussed. A morphogenetic interpretation of the body plan development during embryogenesis, metamorphosis and asexual reproduction in Sponges is proposed. Special attention is given to the analysis of characteristic features of the ontogenesis in Porifera. The book pursues three primary goals: 1) generalization of all existing information on individual development of sponges, its classification and a statement according to taxonomical structure of Porifera; 2) revealing of heterogeneity of morphogenesis and peculiarities of ontogeneses in various clades of Porifera, and also their correlations with the organization, both adult sponges, and their larvae; 3) revealing homology of morphogeneses in both Porifera and Eumetazoa, testifying to the general evolutionary roots of multicellular animals, and peculiar features of sponges' morphogeneses and ontogenesis. This book will be of interest to embryologists, zoologists, morphologists and researchers in evolutionary biology.

COMPARATIVE EMBRYOLOGY OF ANGIOSPERMS is a review of the developmental processes leading to sexual reproduction in flowering plants. On the basis of embryological data and certain evidences from other areas of study, it lays special emphasis on the relationship among and within the families and orders of angiosperms. Occasionally, inaccuracies in observation and interpretation are pointed out, alternative interpretations offered, gaps in our knowledge highlighted, and prospects outlined. The text is documented with 36 tables, 376 figures, and about 5000 literature citations, which contribute to making this book comprehensive. Besides students and research workers interested in angiosperm embyology, taxonomists, plant breeders, agriculturists, and horticulturists will also find much useful information in this treatise.

Thirty-four years have elapsed since the publication of the late Professor P. Maheshwari's text, An Introduction to the Embryology of Angiosperms, a work which for many years served as an invaluable guide for students and a rich source book for research workerso Various texts dealing with sections of the braad spectrum oftopics encompassed by Maheshwari in his book have appeared in the interim, but a compendious modem work dealing with the whole field has been lacking. This present volume splendidly meets the need, and it is altogether fitting that Professor B. M. lohri, long an associate and close colleague of Professor Maheshwari and himself a prolific contributor to the subject, should have undertaken the task of editing it. When Maheshwari wrote, it was stiIl feasible for one author to handIe the subject, but today even someone with his fine bread th of vision and depth of understanding could not, alone, do it justice. So the effort has to be a collaborative one; and Professor lohri's achievement has been to bring together a team of authoritative collaborators, assign them their responsibilities, and put them to work to produce a text as integrated in its treatment as the diversity of the subject would allow. The product vividly illustrates the advances that have been made in the study of angiosperm reproductive systems in the last 30 years, and the book is surely destined to become the new standard for student and researcher alike.

Emphasizing the changes worked by circulation and copying, interpretation and debate, this book uses the case to explore how pictures succeed and fail, gain acceptance and spark controversy. It reveals how embryonic development was made a process that we can see, compare, and discuss, and how copying - usually dismissed as unoriginal

Because of the recent advances in embryo modeling techniques, and at the request of the Office of Science Policy in the Office of the Director at the National Institutes of Health, the National Academies of Sciences, Engineering, hosted a 1-day public workshop that would explore the state of the science of mammalian embryo model systems. The workshop, which took place on January 17, 2020, featured a combination of presentations, panels, and general discussions, during which panelists and participants offered a broad range of perspectives. Participants considered whether embryo model systems - especially those that use nonhuman primate cells - can be used to predict the function of systems made with human cells. Presentations provided an overview of the current state of the science of in vitro development of human trophoblast. This publication summarizes the presentation and discussion of the workshop.