The Natural History Library $1.45 NIO :^rom Philosoph HOMER W. SMITH A Doubleday Anchor The American Museum of Natural History Clifford Harding BIOLOGY DEPARTMENT FROM FISH TO PHILOSOPHER HOMER w. SMITH is onc of the outstanding figures in modem physiology. Presently Chairman of the Depart- ment and Professor of Physiology at the New York Uni- versity School of Medicine, he has undertaken extensive researches on the structure and function of the kidney, and has written, in addition to numerous scientific arti- cles, the following key works on the subject: The Physi- ology of the Kidney; The Kidney: Structure and Func- tion in Health and Disease; and Principles of Rerml Physiology. Bom in Denver, Colorado, in 1895, ^^ prepared for a career in medicine at the University of Denver where he received his A.B. degree, and went on to Johns Hopkins University for his Sc.D. degree. As a National Research Council Fellow in Physiology, Dr. Smith studied for two years at the Harvard Medical School. A recipient of the Passano and Lasker awards, and a former Guggenheim fellow, he has also been awarded the Presidential Medal for Merit. Dr. Smith is a member of the National Academy of Sciences, the American Physiological Society, the Ameri- can Society for Biological Chemists, the Association for American Physicians, the Society for Experimental Biol- ogy and Medicine. Formerly president of the Mount Desert Island Biological Laboratory, he is presently a trustee of the Bermuda Laboratory for Biological Re- search. He is also the author of Kamongo: The Lungfish and the Padre, a novel; The End of Illusion, and Man and His Gods. THE NATURAL HISTORY LIBRARY makes available in paperback format books of enduring interest in the life and earth sciences. Published in co- operation with The American Museum of Natu- ral History by Doubleday Anchor Books, this series introduces the student and the general reader to the study of man—his origins, his na- ture, and his environment—and to the whole natural world, from sub-microscopic life to the universe at large. The series is guided by a board at The Ameri- can Museum of Natural History consisting of: Franklyn M. Branley, Associate Astronomer, De- partment of Astronomy; Charles M. Bogert, Chairman and Curator, Department of Herpetol- ogy; E. Thomas Gilliard, Associate Curator, De- partment of Ornithology; Gordon F. Ekholm, Curator of Mexican Archaeology, Department of Anthropology; and Bobb Schaeffer, Curator, De- partment of Vertebrate Paleontology. FROM FISH TO PHILOSOPHER HOMER W. SMITH WITH 11 ILLUSTRATIONS PUBLISHED IN CO-OPERATION WITH TEE AMERICAN MUSEUM OF NATURAL HISTORY THE NATURAL HISTORY LIBRARY ANCHOR BOOKS DOUBLEDAY & COMPANY, INC. GARDEN CITY, NEW YORK The Natural History Library Edition, 1961 by special arrangement with Little, Brown and Company and CIBA Pharmaceutical Products Inc. Copyright © 1961 by The American Museum of Natural History Copyright 1953, 1959, by Homer W. Smith All Rights Reserved Printed in the United States of America FOR MARGARET AND HOMER WILSON SMITH ACKNOWLEDGMENTS Grateful acknowledgment is due the Yale University Press for permission to use the quotations from Dr. George Gaylord Simpson, pp. 15-17, 175; to the Illus- trated London News for permission to reproduce Figure 11, and to many colleagues, particularly Mr. James W. Atz, Dr. Frank A. Beach, Dr. C. M. Breder, Dr. George L. Clarke, Mr. Christopher Coates, Dr. George Gamow, Dr. Chester W. Hampel, Dr. Donal Sheehan, Dr. George Gaylord Simpson, Mr. Peter Smith, and Dr. S. Bernard Wortis for advice on tech- nical matters. The writer is also indebted to Mr. Philip S. Miller, Acting Chief of the Music Division of the New York Public Library, for Sir James Paget's account of the Mendelssohn presto; to Mr. Harold C. Schonberg, of the Music Department of The New York Times, for call- ing his attention to the Godowsky-Chopin 'Badinage*; and to Mr. Abram Chasins, Mr. Harold Lawrence, Mr. Sigmund Spaeth, Miss Rosalyn Tureck, and Mrs. Nathaniel W. Leonard for numerous suggestions. He is particularly grateful to Dr. David Saperton for aid in the analysis of music presented here, and for mak- ing available for counting his copies of Godowsky*s music. Special acknowledgment must be paid to Miss Mary LoRENC for her careful execution of the illustrations. FOREWORD The way the kidney works is described clearly and ex- plicidy in this book—a story of vertebrate evolution and adaptation seen through kidney function. The author, Dr. Smith, is an eminent kidney physiologist whose broad range of interests takes him to the realm of evolu- tion—without ever leaving the kidney. He describes how the kidney functions on different phylogenetic levels and how it facilitates the adaptation of organisms, such as the estivating lungfish ("Kamongo" of an earlier book), to highly speciahzed environments. The importance of the kidney cannot be overesti- mated; it removes and excretes the waste products of cell metabolism and it maintains, in constant and rela- tively equivalent composition, the body fluids which bathe the cells. The kidney works closely with the blood system, removing the wastes from it and adjusting the level and balance of sugars, salts, and water as the blood courses through the fine structure of the kidney. In fact, its basic unit, the nephron, is made up of a tuft of in- tertwined blood capillaries (the glomerulus) closely aligned with a kidney tubule. Through mechanisms of filtration and reabsorption, the balance of the internal environment is maintained. This constancy of environ- ment is critical to vertebrate evolution and adaptation. In addition to his comprehensive survey, Dr. Smith deals with the problem of the origin of the earliest verte- brates, ancient fossil fishes called the ostracoderms. XU FOREWORD which appeared in the fossil record 450,000,000 years ago. Here he postulates that the first fishes appeared in fresh water because the kidney of primitive types of fishes living today is adapted to life in fresh water. It has a large glomerulus, and therefore it is able to filter and excrete the large quantities of water which con- tinuously dilute body tissue. When the book was first published in 1953, paleontologists agreed that the first fishes probably appeared in a fresh-water habitat, that Dr. Smith's evidence was critical, and that it strength- ened the paleontological findings: the fauna, flora, and chemical composition of certain geological beds sug- gested that they were laid dov/n in fresh water. But now the fresh-water habitat theory is no longer completely acceptable. Newly discovered facts about other geologi- cal beds, their faima, flora, and chemical make-up, and the time in which they were laid down, suggest that the first fishes appeared in a marine habitat. Recently at Harvard, where A. S. Romer leads the exponents of the fresh-water habitat theory. Dr. Smith was asked about the evidence presented by the Chicagoan, R. H. Deni- son, in support of the salt-water theory. Dr. Smith re- phed that he had read Denison's work carefully, admired it, and felt it merited serious consideration. However, he maintained that his loyalties remain with his Cambridge colleague, Dr. Romer. These two views are in strong op- position, and they will force important revisions when more facts are gathered and analyzed. The problem is intriguing and one that needs solution. Students of pa- leontology are now working on the problem; this volume should be of considerable importance to their studies. EVELYN SHAW Research Associate in Animal Behavior March 1961 The American Museum of Natural History CONTENTS I. EARTH 1 n. EVOLUTION 11 ni. THE PROTOVERTEBRATE 21 IV. THE KIDNEY 3I V. THE ELASMOBRANCHS 53 VI. THE LUNGFISH 7I Vn. THE AMPHIBIA 85 Vin. THE BONY FISHES IO3 EX. THE REPTILES AND BIRDS 11/ X. THE MAMMALS I3I XI. ANIMALS THAT LIVE WITHOUT WATER I47 xn. MAN 175 xni. CONSCIOUSNESS 197 TECHNICAL NOTES AND BIBLIOGRAPHY 227 INDEX 283 ILLUSTRATIONS Figure 2 in the center of the hook shows in synopsis the evolution of the vertebrates in relation to a salt-water (darkly shaded) and fresh-water (lightly shaded) habi- tat. The irregular curve illustrates mountain-building epi- sodes (geologic revolutions) which have importantly in- fluenced this evolutionary history. The time scale is such that the Pleistocene era (one million years in length) and Recent Time (about twenty- five thousand years) could not be included, and these are merely suggested by the heavy line at zero time. The entire period encompassed by documented history is only about six thousand years, or one hundred-thou- sandth of the interval elapsing since the opening of the Paleozoic era (Cambrian period), when fossilized ani- muls first begin to appear in the sedimentary rocks. 1. Cross Section of the Earth 2. Synopsis of Evolution of Vertebrates 3. Simpson's Alphabet Analogy 4. The Hypothetical Protovertebrate Three Types of Armored Fishes, or Ostracoderms, from the Devonian Three Types of Emypterids from the Silurian 5. Four Stages in the Evolution of the Vertebrate Nephron 6. Evolution of the Early Fishes 7. The Lungfish, Protopterus, in Estivation in a Block of Mud 8. The Carboniferous Amphibia XVI ILLUSTRATIONS 9. The Reptiles and Mammals Were Evolved from Stock Which Had Acquired the Amniotic Egg 10. Diagrammatic Representation of the MammaUan Nephron 11. Australopithecus africanus AUTHOR'S NOTE This book is based in part on studies in the comparative physiology of the kidney carried out by the writer dur- ing the past thirty years at the New York Aquarium, the Mount Desert Island Biological Laboratory at Sahsbury Cove, Maine, the Bermuda Biological Station for Re- search, the University of Virginia School of Medicine, and, since 1928, at New York University College of Medicine, in later years supported by the Common- wealth Fund and the National Heart Institute of the Na- tional Institutes of Health.