Book - The Frog Its Reproduction and Development

By Roberts Rugh, Ph.D.

The Blakiston Company 1951

Book - The Frog Its Reproduction and Development

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Preface

This book has been written for three reasons. First, since T. H. Morgan's "Development of the Frog's Egg" (1897), there has been no book written specifically on this subject. His was a most excellent treatise, still remarkably accurate. Second, with the accelerated interest in the experimental approach to the study of embryology, stimulated by Spemann in Germany and Morgan and Harrison in this country, and implemented by a host of their students, there has been accumulated a large volume of information not available in 1897. It is important that the description of normal embryology, aided by this experimental approach, be brought up to date for the frog. Third, with the discovery that the frog can be induced to ovulate and provide living embryos at any time of the year, these embryos have become one of the major test organisms in experimental embryology. It is also being used increasingly in the related scientific disciplines such as physiology, cytology, and genetics.

The author disclaims any fundamental originality in this book. All of the previous investigators and authors touching on the normal embryology of the frog, from whose works much information has been gathered, have been listed in the Bibliography. It is they who have done much of the "spade work" for this book and the student is encouraged to refer to these original sources. However, the author has described the normal development of the frog to more than 5,000 students during 19 years of teaching, as a result of which an intimate personal knowledge of all phases of frog embryology has inevitably accrued. Further, the author organized one of the first laboratory courses for experimental embryology in which the major experimental form was the frog egg and embryo. From these two major lines of work a personal interpretation of the development of the frog egg and embryo has developed, built on the broad structural foundation laid by a host of other workers. The author is responsible, however, for any novelty of interpretation.

The author has no intention of claiming any suggestion of finality, in spite of a didactic presentation. the objective presentation of the truth, as far as it can be apprehended at the moment, is the extent of one's responsibility. Accuracy should be the moral and ethical responsibility of every author of a treatise on a scientific subject. To the best of the author's knowledge, the descriptive material of this book is demonstrably accurate.

The author, as a teacher, has found it increasingly important that there be a common language by which information can be imparted to the student. This necessity is met in part by a Glossary of embryological terms, readily accessible to the student and rigidly adhered to by the instructor. For this reason, the book breaks with tradition to include a complete Glossary of some 750 words. A definition will often clarify or crystallize a complicated and detailed description. Therefore it is hoped that the student will increase his functional vocabulary to the extent of the appended Glossary.

The author is also an enthusiastic advocate of the visual elucidation of the oral description. Most illustrations are useful, some are indispensable. Therefore a profusion of illustrations appears in this book, most of which are original and based on direct observation of the egg and embryo. In a few cases excellent illustrations of other workers have been borrowed or slightly modified for inclusion in this text.

The seed for this book was planted early in the author's mind while he was being initiated into the field of embryology by Professor Robert S. McEwen of Oberlin College. During a long period of incubation the plan slowly matured. Experience, gained over the years in teaching and learning from the response of interested students, helped to bring into clearer focus the aims to be sought for in this book as a teaching text. The execution of the task and the finished form presented here could not have been attained at this time but for the invaluable assistance given by the publishers and their staff. Thanks are due to Miss Marie Wilson and to The Blakiston Company — especially to Mr. William B. McNett and Miss Gloria Green of the Art Department who helped with the illustrations; to Mr. Willard Shoener of the Production Department; and most particularly to Miss Irene Claire Moore and Dr. James B. Lackey of the Editorial Staff. Special acknowledgment is also given to the General Biological Supply House of Chicago, whose illustration of the frog is used so effectively on the title page. It remains for the professor and the student of embryology to evaluate the fruits of our common labors.

Embryology is a basic subdivision of biology. From it stem the anatomy, the histology, and the physiology of the adult. To understand it well is to aid in the comprehension of the other biological disciplines.

To know one's self it is not sufficient to study the present-day transiency. Such a study will be enhanced to the degree that it is supported by a knowledge of what preceded the present. To be a Jacques Loeb and thus be qualified to make such a statement as "The most uninteresting thing I know is the normal development of an egg," one has first to know formal, basic, morphological embryology as thoroughly as it is possible to comprehend. It is only then that we can appreciate and intelligendy apply the experimental method to the problems of embryology. Possibly, were Loeb alive today, he would be one of the first to admit that we know less about the normal development of the frog than we thought we knew at the time of his statement. Even for the ten-thousandth time, the formation of the tension lines of the first cleavage furrow or the initial involution of the gastrula are still among the most challenging of unsolved mysteries both to the author and to his students.

The adult "organism as a whole" is, in part at least, an expression of its earlier experiences as an embryo. We may even have to admit that the ultimate personality begins its realization at the moment of fertilization. Certainly, to by-pass a study of the development of the most rapid, the most dynamic, the most plastic stage of one's entire physical existence is to miss the sum and substance of life itself. It is the author's firm belief that anyone who completely understands the mechanism of normal embryonic development will, to a comparable degree, understand life at any level. Further, in understanding the embryology of the frog completely, one would come very close to an understanding of the basic principles of development of any form whatsoever.

Roberts Rugh

New York City,

June 1950.

Contents

• Preface
• Chapter One - Introduction
  • The Period of Descriptive Embryology
  • The Period of Comparative Embryology
  • The Period of Cellular Embryology
  • The Period of Experimental Embryology
  • The Embryologist as a Scientist
  • Why the Embryology of the Frog?
  • Some General Concepts in Embryology
    • Biogenesis, Biogenetic Law — The Law of Recapitulation, Epigenesis vs. Preformationism, Soma and Germ Plasm, The Germ Layer Concept
  • The Normal Sequence of Events in Embryology
• Chapter Two - General Introduction to the Embryology of the Leopard Frog, Rana pipiens
• Book - The Frog Its Reproduction and Development_3Chapter Three - Reproductive System of the Adult Frog: Rana pipiens
  • The Male
    • Secondary Sexual Characters
    • Primary Sexual Characters
    • Reproductive Behavior
    • Accessory Structures
  • The Female
    • Secondary Sexual Characters
    • Primary Sexual Characters
• Chapter Four - Fertilization of the Frog's Egg
  • Completion of Maturation of the Egg
  • Penetration and Copulation Paths of the Spermatozoon
  • Symmetry of the Egg, Zygote, and Future Embryo
• Chapter Five - Cleavage
• Chapter Six - Blastulation
• Chapter Seven - Gastrulation
  • Significance of the Germ Layers
  • Origin of Fate Maps
  • Gastrulation as a Critical Stage in Development
  • Pre-gastrulation Stages
  • Definition of the Major Processes of Gastrulation
  • Gastrulation Proper
• Chapter Eight - Neurulation and Early Organogeny
  • Neurulation
  • Early Organogeny
  • Surface Changes
  • Visceral Arches
  • Origin of the Proctodeum and Tail
  • Internal Changes
• Chapter Nine - A Survey of the Major Developmental Changes in the Early Embryo
• Chapter Ten - A Survey of the Later Embryo or Larva
• Chapter Eleven - The Germ Layer Derivatives
  • The Ectoderm and Its Derivatives
    • The Brain
    • The Spinal Cord
    • The Peripheral Nervous System
    • The Organs of Special Sense
    • The Cranial Nerves
    • The Spinal Nerves
    • The Neural Crest Derivatives
    • The Stomodeum and Proctodeum
• Chapter Twelve - The Endodermal Derivatives
  • The Mouth (Stomodeum, Jaws, Lips, Etc.)
  • The Foregut
  • The Midgut
  • The Hindgut
• Chapter Thirteen - The Mesodermal Derivatives
  • The Epimere (Segmental or Vertebral Plate)
  • The Mesomere (Intermediate Cell Mass)
  • The Hypomere (Lateral Plate Mesoderm)
• Appendix: Chronological Summary of Organ Anlagen Appearance of Rana pipiens
• Glossary of Embryological Terms
• Bibliography for Frog Embryology
• Index

Historic Disclaimer - information about historic embryology pages

Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Reference

Rugh R. Book - The Frog Its Reproduction and Development. (1951) The Blakiston Company.

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Cite this page: Hill, M.A. (2024, April 23) Embryology Book - The Frog Its Reproduction and Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_The_Frog_Its_Reproduction_and_Development

What Links Here?

© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G

Historic Disclaimer - information about historic embryology pages

Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

---

Cite this page: Hill, M.A. (2024, April 23) Embryology Book - The Frog Its Reproduction and Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Book_-_The_Frog_Its_Reproduction_and_Development

What Links Here?

© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G