The contributions to this volume were presented at a Symposium entitled "Current Topics in Muscle and Nonmuscle Motility" held in Dallas 19-21 November 1980 under the auspices of the A. Webb Roberts Center for Con tinuing Education, Baylor University Medical Center Dallas, and the Univer sity of Texas Health Science Center at Dallas. This very useful opportunity for a group of active investigators in motility to meet and discuss their latest findings was made possible in part by the income from an endowment fund established by a generous gift from Dr. Albert P. D'Errico in the Baylor University Medical Center. Dr. D'Errico was the first formally-trained neurosurgeon to practice in the Dallas area, the first Chief of Neurological Surgery, and a member of the Medical Board of the Baylor University Medi cal Center Dallas (1947 -1964). The income from this fund is used to promote the dissemination of up-to-date information in the Neurosciences, to provide intellectual stimulation, to add to the fund of knowledge, and improve the skills of neurosurgeons, neurologists, internists, and others in specialized fields of medicine. We are all indebted for this generous gift that made this enriching educational experience possible. We are also grateful for support the Symposium received from Electron Microscopy Sciences, Forma Scien tific, J. E. O. L. USA, Inc. , Ladd Research Industries, M. J. O. Diatome Co. , Or ganon Co. , Upjohn Co. , G. D. Searle & Co. , and Smith, Kline and French. Robert M.

to Mechanics of Human Movetnent by James Watkins Scottish School oj Physical Education lordanhill College oj Education, Glasgow, Scotland 1983 M. TP PRESS LIM. ITED . . . . a member of (he KLUWER ACADEMIC PUBLISHERS GROteP BOSTON / THE HAGUE! DORDRECHT ! LANCASTER " Published by MTP Press Limited Lancaster, England Copyright (c) 1983 MTP Press Limited Softcover reprint of the hardcover 1st edition 1983 First published 1983 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission from the publishers. British Library Cataloguing in Publication Data Watkins, James An introduction to mechanics of human movement 1. Human locomotion I. Title 612476 QP303 ISBN-13: 978-94-011-7815-0 e-ISBN-13: 978-94-011-7813-6 DOl: 10. 1007/978-94-01\-7813-6 Typeset by Blackpool Typesetting Services Ltd. , Blackpool. Bound by WBC Bookbinders Ltd. , Maesteg, Mid Glamorgan. Contents PREFACE vii INTRODUCTION Mechanics of human movement 1 1. 1 1. 2 Forms of motion 2 1. 3 Units 3 LINEAR MOTION 2 2. 1 Distance and speed, displacement and velocity 4 2. 2 Acceleration 11 2. 3 Vector and scalar quantities 13 2. 4 Mass, inertia and linear momentum 21 2. 5 Force and Newton's First Law of Motion 21 2. 6 Newton's Law of Gravitation (law of attraction); gravity and weight 23 2. 7 Newton's second law of motion; the impulse of a force 27 2. 8 Units of force 31 2.

The Eighth Annual Research Conference of the American Institute for Cancer Research, held in Washington, D.C., September 3-4, 1998, was on the subject "Colon Cancer Prevention: Dietary Modulation of Cellular and Molecular Mechanisms," with participants representing various disciplines interested in this area. One of the speak ers provided an appropriate quote from 17th century physician Thomas Adams: "Pre vention is better than healing because it saves the labor of being sick," which aptly describes the need for the prevention of cancer. An overview of normal and abnormal colonic development emphasized that although the typical human colon undergoes 1013 cell divisions by age 60, with the asso ciated possibilities for error, relatively few colon tumors develop. Since dietary modu lation leads to extremely small changes in colonic cells over a long period, animal models are useful to time, observe, and delineate the events associated with colon cancer. In the development colon cancer, the inactivation of the adenomatous polyposis coli (Apc) gene is one of the earliest known events. Normally Apc downregulates the cellular protein beta-catenin, but this is lost during cancer development. Beta-catenin may itself be an oncogene; it has a short half-life, but it is stabilized by binding to is more prevalent in the cell nucleus, the gene shuttles caherin. Although the Apc between the nucleus and the cytoplasm."

The various chapters of this monograph were originally presented as papers in a Symposium on Joints and Bones which the editor organized for the VIII Inter national Congress of Anatomists held in Wiesbaden, Germany in August 1965. Each chapter represents original research on the structure and/or function of joints and bones. Preparing the manuscripts of these papers for publication required more time than originally anticipated and the editor hereby acknowledges his sincere appre ciation to the various authors for their help and patience. He also wants to express his special thanks to Mrs. ANTOINETTE CATRON, his editorial assistant, without whose help the task would still be unfinished. The interest and assistance of the staff of Springer-Verlag in the publication of this monograph is also greatly appreciated. Ann Arbor, Michigan, USA. February 1966 F. GAYNOR EVANS Contents Electron Microscopy of Normal Synovial Membrane. D. V. DAVIES, and A. J. PALFREY .............................. 1 Biomechanics and Functional Adaption of Tendons and Joint Ligaments. A. VnDIK . . . . . . . . . . . . . . . . . . . . . . . . .. . 17 . . . . Dynamic Considerations in Load Bearing Bones with Special Reference to Osteosynthesis and Articular Cartilage. J. M. ZAREK .. . . . . . . . 40 Intravital Measurements of Forces Acting on the Hip-Joint. N. RYDELL. .. 52 The Ergonomic Aspects of Articular Mechanics. M. A. MACCONAILL . . . . 69 A Longitudinal Vital Staining Method for the Study of Apposition in Bone. M. ]. BAER, and]. L. ACKERMAN. . . . . . . . . . . . . . . . . 81 . . . An Evaluation of the Use of Bone Histology in Forensic Medicine and Anthro pology. D. H. ENLOW. . . . . . . . . . . . . . . . . . . . . 93 . . . .

Several methods have been used to demonstrate the vasculature of different organs in man and other species. Many attempts to evaluate the precise microangioarchitecture of organ systems remained unproductive, others were controversial. The development of electron microscope in thirties opend new perspectives in researching microvascular systems. Transmission electron microscopy provided a two-dimensional view on microcirculatory system at higher magnifications, however, its standardization was delayed unnecessarily. The use of methyl methacrylate and related compounds for obtaining replicas of vascular beds, and their study in scanning electron microscope opened a new window in micromorphological research. For the first time, a three-dimensional image analysis of the vascular system was possible. The microvascular corrosion casting method has meanwhile attracted the interest of many contemporary scientists. Its application to medical and biological problems justify it to be used as a routine method for microvascular investigations. The first investigators who used this method, focused either on methodological details or they dealt with the normal microanatomy of organs. The advantages of this method in demonstrating pathological microvascular patterns are also evident.

The ability to "immortalize" immunologically-useful cells by hybridization with a unique cancer cell has revolutionized serological studies and has revealed new potential applications in all fields of biological sciences. This volume presents the studies from a highly successful national symposium on Hybridomas and Cellular Immortality held November 1981 in Houston, Texas. The individual chapters exhibit the diversity of topics discussed during the meeting. These include emphasis on the origin of antibody diversity, Band T lymphocyte differentiation, applications of monoclonal antibodies in studies of histocompatibility, tumor, and viral antigens, plus the use of somatic cell hybridizations for studying T cell products. Three papers focus on the emerging methodologies of in vitro primary immunizations for both humoral and cell-mediated immunities, relevant for coupling with hybridoma technology. There is a useful mix of general (methods) and specific (applications) chapters. A unique aspect of the book is the presentation of both recent research findings with concise descriptions of the state of the art methodologies. It is anticipated that this work will be of interest to a wide audience of practioners in biomedical research. Hopefully, the information contained will foster new and imagi native ideas in hybridoma applications. Baldwin H. Tom, Ph.D. James P. Allison, Ph.D. vii CONTENTS PART L INTRODUCTION TO HYBRIDOMAS 1 Somatic Cell Hybrids and Hybridomas Baldwin H. Tom 3 1. Somatic Cell Hybrids 8 Hybridomas. * * * * * 2.

Leading workers in the field of human reproduction provide both basic knowledge and useful practical information in this book about the most critical phase in the development of a new human being: the first twelve weeks of life. The period from fertilization and implantation to the end of the first trimester is still insufficiently understood and marks a new frontier. The knowledge necessary for applying our present diagnostic capabilities and for venturing into the problematic areas of fertilization technology and embryonic treatment is made easily available in this comprehensive textbook. The book is divided into two parts. The first presents basic information about physiology, anatomy, in vivo investigations, biochemistry and legal aspects. The second part focuses on pregnancy development, monitoring and the clinical diagnosis and management of disorders in the early stages of life. A full section is devoted to assisted conception and the newest possibilities in fertilizationtechnologies, whereby the ethical aspects are also discussed.

The advantages of obtaining a completely defined environment for the growth of cells in vitro were recognized very early in the history of cell culture (Lewis and Lewis, 1911). Continued interest in the nutritional requirements of cells in vitro and in providing an optimal environment for cells led to the development of the complex nutrient mixtures available today in many media (Waymouth, 1972; Ham, 1965). However, serum remained an essential component of medium for the growth of most cell types in culture. The question of what factor (or factors) in serum was essential for cell growth and survival remained unanswered for several decades. Initially, experiments were designed to purify the "active component" of serum for the growth of cells in culture. These experiments identified fetuin (Fisher et at., 1958) and nonsuppressible insulinlike activity (Temin et at., 1972) as important components of serum. However, the complexity of serum and the very low levels of active components in serum hindered progress in identi fying and isolating serum factors."

In this book, concerned with the spatial and structural repre- sentation of the cell and its particular specializations, the author hasdeviatedconsiderablyfrom the usual planfor other books related to this subject and has presented the illustrative material in the form of detailed and accurate drawings. The layout of the book provides the reader with a briefnarrative accountoftheparticularorganelleaccompanied byafull-plate illustration on the facing page. Most ofthe narrative accounts areaccompaniedbyashortbibliographyofgermanereferences in the event the reader desires to pursue the subject matter in greater depth. In my estimation there is no other presentation currentlyavailablewhich utilizes thisapproach to demonstrate the cellular components and their associated morphophysi- ology with such elegance. Thetextisclearlywrittenand,althoughtheindividualaccounts are brief, they are highly informative with all ofthe important details being provided. The accuracy ofthe textural presenta- tions and the continuity ofexpression provide strong evidence that the author has spent an enormous amount of time in preparing the text and in painstakingly drawing the illustra- tions. Certainly, an obvious strength ofthis volume is the high qualityoftheillustrativerenditions, allofwhichweredrawnby Dr. KRSTIC. These attest to the profound and comprehensive nature of the author's knowledge of the field of cellular and structural biology. This book is truly a work oflove and art by one who is gifted both didactically and artistically. Dr. KRSTIC should be con- gratulated for providing us with an extremely accurate and detailedaccountofthe 2-dimensional, andinmanycasesthe 3- dimensional, view of the cell and its component organelles. It has no equal.

The present volume contains the edited transcript of a Totts Gap Colloquium held May 19-21, 1980 sponsored by the Muscular Dystrophy Association. The aim of the colloquium was to bring into focus data relating to cell membranes that might contribute to understanding the pathogenic mechanism of Duchenne muscular dystrophy. A major impediment to progress in understanding the patho genesis of muscular dystrophy has been the failure, so far, to identify the basic genetic defect. Pending the identification of the genetic lesion in Duchenne dystrophy and, in view of scattered but persistent indications of a basic membrane disturbance, it seemed worthwhile to explore in open dialogue the current state of knowledge of membrane morphology and chemistry with an eye to possible leads for further investigation. The participants, drawn from a variety of interested disciplines, attempted to synthesize and reconcile their findings and to identify crucial areas of ignorance in need of exploration. For the most part they avoided specialized jargon and spoke in a language that could be understood by the rest of the group. Apart from providing a review of widely varying approaches to the study of the composition and behavior of cell membranes, the discussions brought together current think g on strategies and approaches to the study of the pathogenesis of muscular dystrophy. Already the personal contacts made at the colloquium have led to new inter-institutional collabora tive investigations."

Alfons Staudach has been a long-time member of the Anatomic Institute of Karl Franzens University in Graz, where he has devoted particular atten tion to the deeper understanding, appreciation and visualizion of gross ana tomic details. In this work the author has achieved correspondence between sonograms and anatomic sections with a consistency and persuasiveness unequaled in all the previous literature on diagnostic ultrasound. The various planes of section andtheir characteristic features, and indeed the entire format of the text, are designed to provide even the less experienced sonographer with a valuable basis for conducting his examinations. The more experienced reader will find essential information on topographic relations and organ development that is not available in any other work dealing with fetal ana to y. I am certain that my high estimation of this volume will prove justified, and that it will provice its readers with a useful and stimulating resource. Univ. -Prof. Dr. Walter Thiel (Chairman of the Anatomic Institute of the University of Graz) Foreword Anyone setting this book down after an initial perusal must wonder why such a reference was not available ten years ago. The meticulous and fas cinating juxtaposition of gross anatomic sections with sonograms, together with explanatory drawings and many practical guidelines, should enable even the novice accurately to identify details and interpret sonographic findings with precision."

When I was asked by the late Professor Wolfgang Bargmann in 1973 to write the continuation of his review article on the epiphysis cerebri published in the present Handbuch Series in 1943 I felt greatly flattered and readily agreed, not knowing that it is virtually impossible for a single person to cover comprehensively the vast field of pineal research carried out over the last 35 years. Although I have done my best to include as much of the relevant work as possible (up to July 1979), I am constantly haunted by the references I have missed. I sincerely apologize for these omissions: first, to the authors of these papers, who, in addition to working on one of the most stony grounds of biological research, now may experience the additional frustration of not being quoted; secondly, to my fellow pinealogists or pinealogists-to-be, who may carry out painstaking experiments only to find that they have been done before, or who may be led astray because of lack of information. Nevertheless, I do hope that this monograph will fulfil its aim, namely to show how pineal research has progressed over the last 35 years and where it stands today. It is hoped that it will aid in planning relevant experiments and that it shows which approaches to the pineal problem would be better avoided.

Leading international experts contribute to this selection of reviews covering the merging fields of growth factors, differentiation factors, and cytokines. These appear to play fundamental roles in a wide variety of physiological and pathophysiological processes that include the regulation of growth in normal and malignant cells, embryogenesis, the immune response, wound healing, inflammation, and atherogenesis. The major aspects of recent research and development are discussed, providing an important update in this pioneering field.

A different kind of book! The clivus of skull base is an area difficult to reach in neurosurgery, otorhinolaryngolo- gy, maxillo-facial surgery, plastic surgery, reconstructive surgery, and orthopedic surgery. It is for this reason that the various specialities gave found different approaches for different operations.

Since the thalidomide (Contergan) tragedy about 30 years ago the induction of prenatally-induced morphological or functional defects has been an area of extensive research. Risk assessment of prenatally-induced adverse health effects is still a difficult task from both experimental data as well asfrom observations in humans. In the contributions to this book three major aspects are dealt with: - Quantitative extrapolations of experimental data to the situation possibly relevant for man. - The significance for a risk assessment with respect to man of minor or rare structural abnormalities observed in experimental studies - The future need to assess congenital dysfunctions (e.g. of the hormone or the immune system) beside the present evaulation of structural defects. Limitations as well as gaps of the present knowledge in this area of basic and applied research are pointed out. Since the results of prenatally-induced lesions may manifest themselves not only pre- but often not before late postnatally, numerous aspects of structural and functional abnormaldevelopment must be studied in experimental and clinical investigations.

The purpose of these volumes is to provide a reference work for the methods of purifying many of the receptors we know about. This be comes increasingly important as full-length receptors are overexpressed in bacteria or in insect cell systems. A major problem for abundantly expressed proteins will be their purification. In addition to purification protocols, many other details can be found concerning an individual receptor that may not be available in standard texts or monographs. No book of this type is available as a compendium of purification procedures. Receptor Purification provides protocols for the purification of a wide variety of receptors. These include receptors that bind: neurotransmit ters, polypeptide hormones, steroid hormones, and ligands for related members of the steroid supergene family and others, including receptors involved in bacterial motion. The text of this information is substantial, so as to require its publication in two volumes. Consequently, a division was made by grouping receptors by the nature of their ligands. Thus, in Volume One there are contributions on serotonin receptors, adrenergic receptors, the purification of GTP-binding proteins, opioid receptors, neurotensin receptor, luteinizing hormone receptor, human chorionic gonadotropin receptor, follicle stimulating hormone receptor, thyro tropin receptor, prolactin receptor, epidermal growth factor receptor, platelet derived growth factor receptor, colony stimulating factor recep tor, insulin-like growth factor receptors, insulin receptor, fibronectin receptor, interferon receptor, and the cholecystokinin receptor.

H.P. HIGER 1 In the seventeenth century people dreamed about a machine to get rid of evil spirits and obsessions, which were thought to be the main source of mis fortune and disease. I am not going to question this approach, because in a way it sounds reasonable. They dreamed of a machine that would display im ages from the inner world of men which could be easily identified and named. Somehow these are the roots of MR imaging. Of course, we now view disease from a different point of view but our objectives remain the same, namely to make diseases visible and to try to characterize them in order to cure them. This was the reason for setting up a symposium on tissue characterization. About 300 years later the clinical introduction of MRI has great potential for making this dream come true, and I hope that this symposium has con stituted another step toward its realization. When Damadian published his article in 1971 about differences in T1 relaxation times between healthy and pathological tissues, this was a milestone in tissue characterization. His results initiated intensive research in to MR imaging and tissue parameters. Actually his encouraging discovery was not only the first but also the last for a long time in the field of MR tissue characterization.

Endocrinologic investigations during pregnancy have focused in the last decades on placental hormones, the maternal endocrine system and maternal fetal interactions. Less is known about the fetus itself and the interaction of fetal hormonal response and physiological parameters. In this book physiologists, pediatricians and obstetricians active in experimental studies in both physiology and endocrinology combine both aspects of investigations. Historical remarks on the endocrine development of the fetus are followed by observations of the hormonal control of the cardiovascular system. Basic mechanisms of fetal endocrine control such as brain development, fetal growth, fetal behaviour, and thermoregulation are given particular consideration. Finally, carbohydrate metabolism and the mechanism of parturition are outlined.

Dr. Howard House, founder of the House Ear Institute and House Ear Clinic often uses the analogy of planting a seed when referring to establishing the House Ear Institute in 1946. Two grateful patients of Dr. House put forth the idea that his knowledge and innovative skills could be used to expand the understanding of hearing impairment and its treatment. Those two early patients provided the "seed money" to begin the Institute. Since that time, the growth has been phenomenal from a one-man laboratory to a multidisciplinary facility boasting over 175 scien tists, physicians, and support staff, all dedicated to the advancement of otologic research and education. Six years ago after a half-century of remarkable success with prosthetic and device research, the Institute began cultivating a new field of endeavor-cell and molecular biology. Don Nielsen, then the Institute's Executive Vice President for Research and Scientific Director, began exploring the potential for hair cell regen eration and presented his ideas to the Board of Trustees. For a period of six months, we did a lot of fact finding to assess what role the Institute might take in this excit ing new field.

To preserve tissue by freezing is an ancient concept going back pre sumably to the practice of ice-age hunters. At first glance, it seems as simple as it is attractive: the dynamics of life are frozen in, nothing is added and nothing withdrawn except thermal energy. Thus, the result should be more life-like than after poisoning, tan ning and drying a living cell as we may rudely call the conventional preparation of specimens for electron microscopy. Countless mishaps, however, have taught electron microscopists that cryotechniques too are neither simple nor necessarily more life-like in their outcome. Not too long ago, experts in cryotechniques strictly denied that a cell could truly be vitrified, i.e. that all the solutes and macro molecules could be fixed within non-crystalline, glass-like solid water without the dramatic shifts and segregation effects caused by crystallization. We now know that vitrification is indeed pos sible. Growing insight into the fundamentals of the physics of water and ice, as well as increasing experience of how to cool cells rapidly enough have enlivened the interest in cryofixation and pro duced a wealth of successful applications."

In textbooks on anatomy, radiology and stead of the normal one. An "accessory ar- surgery only the "normal" arterial blood tery" is a second artery ip addition to the one normally present, without any specifi- supply is usually described. This "nor- mality", however, is sometimes found in cation of size being made. However, there less than 30% of all cases for some arteries, is no general agreement on whether minute but in over 95% for others. Rarely men- vessels with very small diameters and hard- tioned are deviations in the individual ar- ly any significant blood flow should also be tery's origin, topographical localization and considered. the area it supplies. They can be classified The aims of this book were twofold: first, to into two groups: malformations and vari- extract the frequency of arterial anomalies from the literature (often published in inac- ations. Malformations often have a nega- tive influence on the function of the organ cessible journals) and second, to classity under normal circumstances, e.g. if both these arteries by schematic outlines of the basic types.

Our knowledge of chromaffin tissue has increased enormously since the last comprehensive treatise in this series was published in 1943, chiefly as a result of the development of new histological methods and technical improve- ments. Less than 40 years have passed since the review by MAX WATZKA, and essentially only 25 years were required to accumulate an abundance of revolu- tionizing findings: it was not until 1957 that the carotid body was first studied successfully with the electron microscope. In 1962 the technique of formalde- hyde-induced fluorescence was introduced, yielding a view of adrenergic struc- tures that was completely new and far better than that obtained with the chro- maffin reaction. Immunohistochemistry made it possible to localize enzymes responsible for catecholamine synthesis and to detect peptide hormones. Autora- diographic techniques were used at the level of the electron microscope, the method of chemical sympathectomy was introduced and still other technical improvements could be mentioned. I myself have been interested in chromaffin cells and sympathetic neurons since 1965, when I entered the Department of Histology, University of Vienna, as a medical student. Therefore I have not followed the developments mentioned above retrospectively, but have actually experienced them. Anyone who experi- ences such a development comes to believe that he is well acquainted with the various results and interpretations and is thus capable of objectivity.

The examination of excavated human bone finds is mainly the domain of anthropologists and forensic pathologists, the former working with ancient and historical specimens, the latter with modern finds. The methodological and diagnostic approaches to these skeletal finds are the same, regardless of the time of burial. For physical an thropology, bodily human relics are dealt with as historical resources which give clues to ancient population structure, population develop ment, life-style and subsistence. They are thus able to help scientists understand the present state of human populations. The identification of the finds, whether species diagnosis or the evaluation of individual parameters such as sex, age at death, body size and shape, kinship and pathology follows the same procedure used by forensic patholo gists, whose task is the identification of bodily relics in cases of crime, mass disaster and the like. However, there are other disciplines which benefit from excavated bone finds. Anatomy gains insights into the morphological variability of the skeleton in time and place. The implications for modern physi cians and pathologists are at least two-fold: pathological specimens are suitable to unravel the distribution of many diseases and the susceptibility of individuals to pathogens in pre-antibiotic populations. In addition to this epidemiological aspect, exhumed specimens often exhibit advanced states of bone disease which are no longer or only very rarely present in today's industrialized populations because of efficient surgical intervention and pharmacological treatment."

It is essential to know all of the intricate lymph pathways when performing surgery for esophageal cancer in order to determine the extent of lymph node metastasis. Professor Sato has undertaken, at the request of the TNM Research Committee of the International Society for Diseases of the Esophagus, to map out and classify the lymph nodes of the mediastinum and neck. The beautiful artwork in the Color Atlas of Surgical Anatomy for Esophageal Cancer edited by Professor Sato gives an excellent understanding of the lymph node pathways and their importance in surgical treatment. Minute dissections which represent real life situations, not just the superficial pathways, show the precise location and topographical arrangement of the lymphatics. Full-color schematics are given with the actual dissection illustrations and photographs. The atlas clearly presents the classification of four significant pathways and their communication, the relationship of these pathways en route to the venous angles and the definition and assessment of the most critical nodes. Thoracic surgeons especially will benefit from the excellent illustrations of surgical techniques and the methods for recording the dissected lymph nodes which are presented by Professor Kakegawa. Leading experts fighting esophageal cancer with surgical treatment can use the classification in this outstanding atlas for many years to come as a standard for international comparison. The careful dissection of the lymph nodes may be the best way to improve survival rates after surgery for cancer of the thoracic esophagus.

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."