Book - Human Embryology (1897)

Human Embryology

by

Charles Sedgwick Minot

Professor of Histology and Human Embryology Harvard Medical School, Boston

Four Hundred And Sixty-Three Illustrations

Hew Vocfi The Macmillan Company

London: Macmillan & Co.. Ltd. 1897

Copyright by Charles Sedgwick Minot

1892

To

Carl Ludwig

Professor Of Physioukiy At The University Of Leipzig

In Token of

Respect. Gratitude. And Akptxtion

This Work Is Dedicated

Nv The Author

PREFACE.

The following attempt to present a comprehensive summary of Embryology, as it bears upon the problems of human development, is the result of ten years' labor. I have endeavored to become familiar with the principal facts by my own observation, and with the results of the principal numerous investigations, working over the material into satisfactory form. The reader will find, nevertheless, imperfections of which I am conscious, and perhaps errors, for which I must be responsible. There is probably not a page which might not be enriched with facts already recorded by investigators; certainly not a page which would not be improved by further revision. Notwithstanding these defects, I have the hope that the book will be a useful contribution toward that final and exhaustive collation of embryological facts which the future alone can give us.

I have sought to form an unbiased judgment upon each question, to accept facts of observation without regard to their supposed theoretical bearings ; and to pay due attention to both Schools of Embryology, the Phylogenetic and the Anatomical, in the belief that both are justified. Whenever I have inserted a new observation or opinion, it is indicated as such by the use of the first person. In making my compilation, I have drawn constantly from the embryological manuals of KoUiker, Oskar Hertwig, Balfour and Duval; from the researches of W. His, and from the writings, especially the " Entwickelungsgeschichte der Unke," of Alexander Goette.

In regard to the technical terms, I have made certain innovations.

It seems to me important to make the nmnber of terms as small as is compatible with clearness, and to avoid duplication. Accordingly I have discarded the words ^^epiblast, mesoblasty and hypoblast, ^^ Further it has seemed to me that, as a thorough knowledge of German is indispensable to the student of embryology, it is justifiable.

where no English equivalent is to be found, to adopt such unaltered German terms as have been fully established in embryological literature. Where there has occurred an accepted term in English, French, or German, I have used it in preference to a Greek or Latin derivative.

Whatever merit this work may possess should be attributed to the training in scientific research which I received in Germany and France. I cannot too gratefully acknowledge the unlimited kindness shown me while a student in Leipzig under Professor Carl Ludwig and Professor Rudolph Leuckart; in Paris under Professor Leon Ranvier; and in Wiirzburg under Professor Carl Semper. I would also here express my gratitude to Professor Wilhelm His, to whom I am particularly indebted for his great generosity in permitting me to study his unique embryological collection in Leipzig ; also to the large number of physicians, both in Europe and America, who have supplied me with material to carry on my investigations in human embryology.

Charles Sedgwick Minot.

Harvard Medical School,

Boston, Mass., July 26, 1892.

Table of Contents

1. Introduction
   1. The Uterus
   2. General Outline of Human Development
2. The Genital Products.
   1. History of the Genoblasts and the Theory of Sex
3. The Germ-Layers
   1. Segrmentation ; Formation of the Diaderm
   2. Concrescence : the Primitive Streak
   3. The Mesoilerm and the Coelom
   4. General Remarks on the Germ-Layers
4. The Embryo.
   1. The Medullary Groove, Notochord and Neurenteric Canals, 178
   2. Divisions of the Ccelom ; Origin of the Mesenchyma, . . 192
   3. Origin of the Blood, Blood- Vessels and Heart, ... 211
   4. Origin of the Urogenital System, 230
   5. The Archenteron and the Gill Clefts, 254
   6. The Germinal Area, the Embryo and its Appendages
5. The Foetal Appendages.
   1. The Chorion
   2. The Amnion and Proamnion
   3. The Yolk Sack, Allantois and Umbilical Cord
   4. The Placenta
6. The Foetus.
   1. Growth and External Development of the Embryo and Foetus
   2. The Mesenchymal Tissues
   3. The Skeleton and Limbs
   4. The Muscular System
   5. The Splanchnocoele and Diaphragm
   6. The Urogenital System
   7. Transformations of the Heart and Blood- Vessels
   8. The Epidermal System
   9. The Mouth Cavity and Face
   10. The Nervous System
   11. The Sense Organs
   12. The Entodermal Canal