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CARNEGIE INSTITUTION OF WASHINGTON

Year Book 61

Digitized by the Internet Archive

in 2012 with funding from

LYRASIS Members and Sloan Foundation

http://www.archive.org/details/yearbookcarne61196162carn

CARNEGIE INSTITUTION OF WASHINGTON

Year Book

July 1, 1961 - June 30, 1962

61

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Sixtieth Anniversary

Library of Congress Catalog Card Number 3-16716 Garamond Press, Baltimore, Maryland

Contents

page

Officers and Staff v

Report of the President 1

Reports of Departments and Special Studies

Mount Wilson and Palomar Observatories 3

Geophysical Laboratory 51

Department of Terrestrial Magnetism 209

Committee on Image Tubes for Telescopes 295

Department of Plant Biology 303

Department of Embryology 367

Department of Genetics 435

Bibliography 477

Administrative Reports 479

Report of the Executive Committee 481

Report of Auditors 483

Abstract of Minutes of the Sixty-Fourth Meeting of the

Board of Trustees 497

Articles of Incorporation 499

By-Laws of the Institution 503

Index 507

in

President and Trustees

PRESIDENT

Caryl P. Haskins

BOARD OF TRUSTEES

Barklie McKee Henry Chairman

Henry S. Morgan V ice-Chairman

Garrison Norton Secretary

Robert Woods Bliss1 Amory H. Bradford Omar N. Bradley Vannevar Bush Walter S. Gifford Carl J. Gilbert Crawford H. Greenewalt Caryl P. Haskins Barklie McKee Henry Alfred L. Loomis Robert A. Lovett Keith S. McHugh Margaret Carnegie Miller Henry S. Morgan Seeley G. Mudd William I. Myers Garrison Norton Richard S. Perkins Elihu Root, Jr. William W. Rubey Henry R. Shepley Charles P. Taft Juan T. Trippe James N. White Robert E. Wilson

i Died April 19, 1962.

Trustees continued

AUDITING COMMITTEE

Keith S. McHugh, Chairman Alfred L. Loomis Juan T. Trippe

EXECUTIVE COMMITTEE

RETIREMENT COMMITTEE

Henry S. Morgan, Chairman Amory H. Bradford Walter S. Gifford Caryl P. Haskins Barklie McKee Henry Robert A. Lovett Garrison Norton James N. White Robert E. Wilson

Omar N. Bradley, Chairman Henry S. Morgan Garrison Norton James N. White

COMMITTEE ON ASTRONOMY

FINANCE COMMITTEE

James N. White, Chairman Walter S. Gifford Alfred L. Loomis Henry S. Morgan Richard S. Perkins Elihu Root, Jr.

Seeley G. Mudd, Chairman Amory H. Bradford Crawford H. Greene wait Elihu Root, Jr.

COMMITTEE ON BIOLOGICAL SCIENCES

Alfred L. Loomis, Chairman Margaret Carnegie Miller William I. Myers Charles P. Taft

NOMINATING COMMITTEE

Amory H. Bradford, Chairman Barklie McKee Henry Richard S. Perkins Charles P. Taft

COMMITTEE ON TERRESTRIAL SCIENCES

Juan T. Trippe, Chairman Barklie McKee Henry Richard S. Perkins Robert E. Wilson

VI

Former Presidents and Trustees

PRESIDENTS

Daniel Coit Gilman, 1902-1904 Robert Simpson Woodward, 1904-1920

John Campbell Merriam, President 1921-1938; President Emeritus 1939-1945 Vannevar Bush, 1939-1955

	TRUSTEES
Alexander Agassiz	1904-05	Henry Cabot Lodge	1914-24
George J. Baldwin	1925-27	Seth Low	1902-16
Thomas Barbour	1934-46	Wayne MacVeagh	1902-07
James F. Bell	1935-61	Andrew W. Mellon	1924-37
John S. Billings	1902-13	Roswell Miller	1933-35
Robert Woods Bliss	1936-62	Darius O. Mills	1902-09
Lindsay Bradford	1940-58	S. Weir Mitchell	1902-14
Robert S. Brookings	1910-29	Andrew J. Montague	1907-35
John L. Cadwalader	1903-14	William W. Morrow	1902-29
William W. Campbell	1929-38	William Church Osborn	1927-34
John J. Carty	1916-32	James Parmelee	1917-31
Whitefoord R. Cole	1925-34	Wm. Barclay Parsons	1907-32
Frederic A. Delano	1927-49	Stewart Paton	1916-42
Cleveland H. Dodge	1903-23	George W. Pepper	1914-19
William E. Dodge	1902-03	John J. Pershing	1930-43
Charles P. Fenner	1914-24	Henning W. Prentis, Jr.	1942-59
Homer L. Ferguson	1927-52	Henry S. Pritchett	1906-36
Simon Flexner	1910-14	Gordon S. Rentschler	1946-48
W. Cameron Forbes	1920-55	David Rockefeller	1952-56
James Forrestal	1948-49	Elihu Root	1902-37
William N. Frew	1902-15	Julius Rosenwald	1929-31
Lyman J. Gage	1902-12	Martin A. Ryerson	1908-28
Cass Gilbert	1924-34	Theobald Smith	1914-34
Frederick H. Gillett	1924-35	John C. Spooner	1902-07
Daniel C. Gilman	1902-08	William Benson Storey	1924-39
John Hay	1902-05	Richard P. Strong	1934-48
Myron T. Herrick	1915-29	William H. Taft	1906-15
Abram S. Hewitt	1902-03	William S. Thayer	1929-32
Henry L. Higginson	1902-19	James W. Wadsworth	1932-52
Ethan A. Hitchcock	1902-09	Charles D. Walcott	1902-27
Henry Hitchcock	1902-02	Frederic C. Walcott	1931-48
Herbert Hoover	1920-49	Henry P. Walcott	1910-24
William Wirt Howe	1903-09	Lewis H. Weed	1935-52
Charles L. Hutchinson	1902-04	William H. Welch	1906-34
Walter A. Jessup	1938-44	Andrew D. White	1902-03
Frank B. Jewett	1933-49	Edward D. White	1902-03
Samuel P. Langley	1904-06	Henry White	1913-27
Ernest 0. Lawrence	1944-58	George W. Wickersham	1909-36
Charles A. Lindbergh	1934-39	Robert S. Woodward	1905-24
William Lindsay	1902-09	Carroll D. Wright	1902-08

Under the original charter, from the date of organization until April 28, 1904, the following were ex officio members of the Board of Trustees : the President of the United States, the President of the Senate, the Speaker of the House of Representatives, the Secretary of the Smithsonian Institution, and the President of the National Academy of Sciences .

Vil

Staff

MOUNT WILSON AND PALOMAR OBSERVATORIES

813 Santa Barbara Street Pasadena, California

Ira S. Bowen, Director

Horace W. Babcock, Asst. Director

Halton C. Arp

William A. Baum

Armin J. Deutsch

Olin J. Eggen

Jesse L. Greenstein

Robert F. Howard

Robert P. Kraft

Guido Munch

J. Beverley Oke

Allan R. Sandage

Maarten Schmidt

Otto Struve

Olin C. Wilson

Fritz Zwicky

DEPARTMENT OF TERRESTRIAL MAGNETISM

GEOPHYSICAL LABORATORY

2801 Upton Street, N.W. Washington 8, D. C.

Philip H. Abelson, Director Francis R. Boyd, Jr. Felix Chayes Sydney P. Clark, Jr.1 Gordon L. Davis Gabrielle Donnay Joseph L. England Hugh J. Greenwood Thomas C. Hoering Gunnar Kullerud Patrick L. Parker2 J. Frank Schairer George R. Tilton Hatten S. Yoder, Jr.

52 U Broad Branch Road, N.W. Washington 15, D. C.

Merle A. Tuve, Director L. Thomas Aldrich Ellis T. Bolton Roy J. Britten Bernard F. Burke Dean B. Cowie John W. Firor3 Scott E. Forbush W. Kent Ford, Jr. Stanley R. Hart4 Norman P. Heydenburg Brian J. McCarthy Richard B. Roberts T. Jefferson Smith5 John S. Steinhart Georges M. Temmer Harry W. Wells6

1 Resigned June 30, 1962.

2 Appointed September 1, 1961. s Through September 15, 1961.

4 From September 1, 1961.

5 From June 1, 1962.

6 On leave of absence to serve as State Department Scientific Attache" sta- tioned at Rio de Janeiro, Brazil, through April 30, 1962.

Vlll

Staff continued

DEPARTMENT OF PLANT BIOLOGY

Stanford, California

C. Stacy French, Director Jeanette S. Brown David C. Fork William M. Hiesey Harold W. Milner Malcolm A. Nobs

DEPARTMENT OF EMBRYOLOGY

115 West University Parkway Baltimore 10, Maryland

James D. Ebert, Director David W. Bishop Bent G. Boving Robert K. Burns1 Robert L. DeHaan Irwin R. Konigsberg Elizabeth M. Ramsey Mary E. Rawles

DEPARTMENT OF GENETICS

Cold Spring Harbor Long Island, New York

Berwind P. Kaufmann, Director1 Elizabeth Burgi Helen Gay Alfred D. Hershey Barbara McClintock Margaret R. McDonald

i Retired June 30, 1962.

IX

Staff continued

OFFICE OF ADMINISTRATION

1530 P Street, N.W., Washington 5, D. C.

Caryl P. Haskins President

Edward A. Ackerman Executive Officer

Ruth L. McCollum Assistant to the President1

Marjorie H. Walburn Acting Assistant to the President2

Ailene J. Bauer Director of Publications

Lucile B. Stryker Editor

James W. Boise Bursar; Secretary-Treasurer Retirement Trust

Kenneth R. Henard Assistant Bursar; Assistant Treasurer Retirement Trust

Donald J. Patton Administrative Associate

James F. Sullivan Assistant to the Bursar

Richard F. F. Nichols Executive Secretary to the Finance Committee

Marshall Hornblower Counsel

Staff Members in Special Subject Areas

Tatiana Proskouriakoff Anna 0. Shepard

1 Retired June 30, 1962.

2 Effective from May 21, 1962.

Staff continued

RESEARCH ASSOCIATES

Carnegie Research Associates

William A. Arnold

Oak Ridge National Laboratory

J. D. McGee

Imperial College of Science and Technology, University of London

Jan H. Oort

Leiden Observatory, The Netherlands

Paul Ramdohr

Heidelberg University

C. E. Tilley

Cambridge University

Evelyn M. Witkin

State University of New York

Research Associates of Carnegie Institution of Washington

Louis B. Flexner

University of Pennsylvania

John H. Holland

Logic of Computers Group, University of Michigan

Peter Milner

The Department of Psychology, McGill University, Montreal

Harry E. D. Pollock

Carnegie Institution of Washington

Donald L. Richards

The Cooley Electronics Laboratory, University of Michigan

XI

The Report of the President

I look upon the Carnegie Institution as the most interesting effort the world has known for the development of a national interest in research.

Henry S. Pritchett

in a letter to Major Henry L. Higginson, May 1904

Without the degree of liberty which culture demands even a perfect society will be no better than a jungle. For this reason all authentic creation is a gift to the future.

Albert Camus

"Y Artiste et son temps' '

Actuelles II, chroniques 1948-1953

The difference is infinitely small between a system of labour which leads men to discover the beauty of the world and one which hides it from them. But this infinitely small difference is real, and no effort of the imagination can bridge it.

Simone Weil

"Cette guerre est une guerre de religions'7

Ecrits de Londres et dernieres lettres

THIS YEAR MARKS THE SIXTIETH ANNIVERSARY OF THE CARNEGIE Institution of Washington. Sixty years ago, in 1902, Andrew Carnegie transmitted to a newly elected Board of Trustees a deed of trust conveying the sum of ten million dollars "to found, in the city of Washington, an Institution which with the cooperation of institutions now or hereafter established, there or elsewhere, shall in the broadest and most liberal manner encourage investigation, research, and discovery. . . ." At the end of January in that year, the Trustees elected Daniel Coit Gilman, fresh from the career for which he was already noted as president of the Johns Hopkins University, as first president of the Carnegie Institution, and resolved "to promote original research by systematically sustaining projects of broad scope that may lead to the discovery and utilization of new forces for the benefit of man . . . projects of minor scope that may fill in gaps of knowledge of particular things or restricted fields of research . . . admin- istration of a definite or stated research under a single direction by compe- tent individuals."

It was not the first of Andrew Carnegie's great philanthropic gifts. Far from it indeed. In the last decade of the closing century in Pittsburgh he had established the Carnegie Institute with its natural history museum, its music hall, and its department of fine arts, and had made possible the Carnegie Institute of Technology, grown now to front rank among the

3

4 CARNEGIE INSTITUTION OF WASHINGTON

scientific and technical universities of the nation. In the opening years of the new century he had established the Carnegie Trust for the Universities of Scotland, and the Carnegie Dunfermline Trust in benefit of his native town. Nor was it, by many removes, to be the last. There were to follow the Carnegie Foundation for the Advancement of Teaching, the Carnegie Endowment for International Peace, Carnegie Hero Funds in no less than eleven countries, and finally, in culmination, the Carnegie Corporation of New York. And long before all of them — indeed well before the publication of his pioneering " Gospel of Wealth" in the North American Review in 1889 — he had initiated that career of benefactions which was to be so profoundly influential in all the subsequent shaping of American philan- thropic tradition with the gift of a library to his native Dunfermline.

But the establishment of the Carnegie Institution of Washington marked a new direction in the kinds of institutions made possible by Mr. Carnegie's gift. In fact, it established a new kind of institution for America — the first to be devoted wholly and completely, in intent and in philosophy, to the ideal of research scholarship over wide fronts of science in its broadest, most unfettered, most completely uncommitted aspect. This was a novel concept, and quite obviously, from some of the records of the time, one neither everywhere comprehensible nor even everywhere palatable in a youthful nation with a strongly established pragmatic tradition. It repre- sented, indeed, a notably original idea, which six following decades have shown to be both great and enduring.

Four years after the establishment of the Institution, it had been granted a new Charter by special Act of Congress and had been organized into no less than fourteen departments, representing as many subjects. Over the next five years, definitive judgments were made as to where and how the Institution could work most effectively. One of them made during these years of experiment and trial was to prove crucial. It involved the decision to concentrate the resources of the Institution primarily on the research of its various departments ; to make of it, in essence, an operating rather than a granting scientific organization. By 1911, its endowment more than doubled by subsequent additions by Mr. Carnegie, its departments firmly established but now reduced to ten, the Institution was molded to the purpose, and had taken on essentially the form of organization, that characterize it to this day. Through the following years new departments have arisen, departments have been consolidated, and some departments have been closed, as the needs and the research frontiers of each decade have dictated. Whole fields that were represented in the Institution in 1911, like economics and sociology, historical research, meridian astrometry, nutrition in the medical sense, no longer are included in its program as the resources of the nation in those areas have strengthened and enlarged.

REPORT OF THE PRESIDENT 5

Other fields not represented then but now on the frontiers of research, like modern embryology, molecular and cellular biology, the study of the mechanisms of photosynthesis, have been included in its purview in more recent years. Today there are five instead of ten departments in the Insti- tution. Most originated in planning going back to the very beginning, though the work they conduct today, under the same general titles with which they began, has expanded far beyond the original concepts embodied in those rubrics, and may have wandered far afield from them as well. The Department of Terrestrial Magnetism was founded in 1904, the Geophysical Laboratory in 1906, and a Desert Laboratory, later to become the Division and then the Department of Plant Biology, appeared in 1903. A Solar Observatory for Mount Wilson was planned as early as 1902. Studies of the sun remain at the pioneering fringes of investigation in that part of the Institution to this day. But now the Solar Observatories have metamor- phosed to the complex of giant telescopes included in the Mount Wilson and Palomar Observatories, operated jointly with the California Institute of Technology. To the intensive program of solar investigations of which George Ellery Hale dreamed and which he initiated with his striking discoveries of magnetic fields in the sun have been added a goodly share of the world's most important findings about the farthest reaches of the celestial universe.

But through all the years the major philosophies of the Institution and one major feature of its organizational pattern have stood constant, tested and retested in situation after situation and proved as fresh and relevant today as when they were conceived. The decision made at the outset that flexibility and effectiveness in the kind of research to which the Institution is dedicated can best be achieved through a series of rather small unit laboratories, each mobile and relatively independent, each able to seize the initiative in new and appropriate fields as they appear, yet all sufficiently connected so that they may be of mutual assistance as the needs arise, was a remarkable one, both for its uniqueness at the time and for the subtlety of the vision that dictated it. Over the decades, as research has burgeoned in the nation and groups devoted to research have multiplied, many other experiments in organizational form have been tried. But it is especially interesting that some of the most modern thinking and experimenting in organization for research, in this country as well as abroad, has returned to precisely this pattern as one of the most effective in exploring the dynamic frontiers of scientific knowledge.

Organization, however, is only a framework, vital but at last only supporting. Most significant — and most truly enduring — have been the elements of philosophy and purpose which inaugurated the Institution and which have remained unchanged through all the years : the philosophy that

6 CARNEGIE INSTITUTION OF WASHINGTON

all its resources, all its deepest purposes, are centered in the creative individual, whatever be his field, that in the truest sense he is the uncom- mitted investigator, suitably endowed and suitably protected, whose time, quite literally, is bought by the Institution and then returned as uncon- strained endowment. And with this goes the philosophy, equally deep-seated and equally important, that this freedom from fixed commitment applies to fields of endeavor as well as to men: that high mobility within specific fields, that the unfettered crossing of fields, that the fashioning of uncon- ventionally wide-ranging programs, are subject only to the limitations imposed by Nature and by the judgment of gifted and discriminating investigators, and that making this mobility and this flexibility possible is a principal objective of the Institution.

Over the years that philosophy, and the programs that have followed from it, have led to many pioneering practical discoveries within the Institution. The elucidation of the genetic principles underlying the development of hybrid corn, first accomplished by Shull in the Department of Genetics at Cold Spring Harbor working with East at Harvard, provided the fountainhead for an agricultural innovation which by 1952 was esti- mated to have brought an economic gain for the United States of almost forty billion dollars. For many of the predominantly agricultural countries of the world, moreover, the technique of hybrid corn has provided one of those basic resources which, as Galbraith has recently pointed out, is in the truest sense a fundamental contribution to their economic strength — an advance of really general application. At the same Department, during the second world war, studies of mutations occurring under X-ray bombard- ment in the famous mold Penicillium resulted in the development of a strain of that fungus which produced three to five times as much of the vitally needed penicillin as the highest-yielding strains then known.

In 1925, fully fifteen years before the intensive research on radar for combat in the second world war, Breit and Tuve at the Department of Terrestrial Magnetism, experimenting with a modified Navy transmitter, produced radio pulses and for the first time observed their echoes from the ionosphere. In the course of those experiments, moreover, they detected a curious interference of normal echoes by passing planes — prophecy of the field of radar. At the Geophysical Laboratory, Day and Shepherd early undertook studies in the field of low-expansion quartz glasses that proved basic to the evolution of Pyrex — a program which during the first world war supplied the United States with ninety-seven per cent of its require- ments for optical glass. In 1935 a modified formula for annealing that same Pyrex glass proved fundamental to the manufacture of the mirror for the two-hundred-inch telescope on Palomar Mountain. Later, in the same laboratory, studies by Morey on lanthanum and borate glasses of high

REPORT OF THE PRESIDENT 7

refractive index led to a whole new family of glasses of great importance in the manufacture of photographic lenses — a development having important implications for the second world war. In the Geophysical Laboratory, again, Rankin and Wright as early as 1915 were able to solve the age-old riddle of cement, and their classic work has served ever since as a guide in the chemical aspects of the cement industry. From the same laboratory in later years have come new refractories for the steel industry, studies of natural geothermometers and geochronometers of fundamental concern to practical mining and oil prospecting as much as to fundamental geology, and, as recently as 1959, synthetic diamonds produced with new substrates and under new conditions of pressure.

Such practical innovation within the Institution has not been confined to the substantive aspects of its concerns. In both world wars the Institution played a major role in initiating forms of research organization for armed conflict. In the first war, the scientific and technical role of the Institution overshadowed its organizational one. But in World War II, through its President, the Institution served as a core of thinking and effort from which, in the following war years, the Office of Scientific Research and Develop- ment was to grow and to assume the lead in civilian scientific and technical military development in the nation. Through its activity and its influence, a preponderant share of all the major scientific and technical advances in the military art were achieved, from radar to modern submarine detection to proximity fuzes to nuclear weapons to new and improved prosthetic aids for the war wounded and the war blinded.

But as critical as the technical findings developed from its activities, and in the final analysis perhaps more enduring, was the dramatic and conclusive demonstration of the crucial role that science as a whole must play in our national life in the years to come, in formal peace as in formal war. Experi- ments in the organization of science were initiated in the O.S.R.D. which were ultimately to find fruition in such government instruments for the furtherance of scientific development throughout the nation as the Office of Naval Research and later the National Science Foundation, and in such bodies as the Atomic Energy Commission, whose present organizational patterns, first tested in the Manhattan Project of the Army Corps of Engineers, were likewise pioneered in the O.S.R.D. They were reflected, too, in such special resources of military thinking and planning as the Rand Corporation, founded shortly after the close of the war. Before those wartime demonstrations of the crucial role of science and technology in the very web of our national life had been made, the greater part of the scientific activity of the nation was prosecuted outside the sphere of government and of public funds. Today, probably sixty-five per cent of the total research of the nation is supported by federal funds, and the proportion is continuing

8 CARNEGIE INSTITUTION OF WASHINGTON

to grow. It is a dramatic demonstration of how deeply, in the public view, the scientific and technical development of the nation has, in fact, become the whole nation's concern. This situation has brought its own problems, of a wholly new order of scope and depth. They, too, must be important concerns in the future for the Carnegie Institution.

To have initiated such practical contributions to the public welfare on the scientific and technical fronts, to have participated actively and sig- nificantly in the initiation of major currents of scientific history whose sweep has now carried us to realms far beyond what was remotely imagined even twenty years ago, to have pioneered forms of organization that are today in the furnace of national trial and test, sum to considerable useful achievement, and might be thought, in and of themselves, to justify the vision upon which the Institution was founded and through which it lives today. Yet, in one sense, they represent mere by-products, mere projecting iceberg tips, as it were, of that vision, indicators only of the submerged seven-eighths. That seven-eighths lies in the kingdom of the mind. It lies in that devotion to deeper patterns, the symmetries, the lights and shades of Nature, wherever the search may lead, to which the Institution was originally dedicated, and which, undeviatingly, it pursues today.

That seven-eighths too has been productive of striking innovations in its own realm, and these, possibly in a truer sense than the practical "firsts," stand as proper signatures of the Institution. They range over many fields. While the thinking which underlay the famous Michelson-Morley experi- ment on "ether drift" was yet fresh, Professor Michelson, holder of the first Nobel prize in the natural sciences to be awarded in America, within the Institution repeated the experiment with an accuracy hitherto unattained, giving strong support to the theory of relativity, itself still at the stage of question and of doubt. Within the Institution, too, Michelson repeated with greater refinement that classic work that he had first undertaken as Ensign A. A. Michelson of the United States Navy, determining the velocity of light with a new precision, first across a path between the peaks of Mount Wilson and Mount San Antonio, then in one defined by a mile- long line of evacuated pipe at the Irvine Ranch in southern California. At the Mount Wilson and Palomar Observatories Hale's pioneering discovery that sunspots mark strong magnetic fields has been followed in more recent years by studies of solar magnetism of unprecedented refinement, and by the discovery, among the stars, of the most intense magnetic fields ever observed in any astronomical body. Hubble's studies of the phenomenon of the redshift in stellar spectra led to the theory of the expanding universe, culminating dramatically a year ago in the measurement of the redshift of

REPORT OF THE PRESIDENT 9

by far the most distant celestial object yet recorded. At the Observatories, too, Baade's studies of the structure and stellar composition of galaxies, with those of others, have suggested concepts of stellar evolution, of growth and decay, undreamed of as little as a quarter century ago.

At the Department of Terrestrial Magnetism a series of conferences on theoretical physics, held shortly before the second world war in cooperation with the George Washington University, among other things stimulated the suggestion that the source of energy in the sun and the stars is a nuclear reaction involving carbon — a notion leading within the next year to a classical model of the hydrogen-helium reaction now familiar as one of the accepted sources of stellar energy, ancillary to the hydrogen-deuterium- helium reaction recognized in recent years as more important. In the Geophysical Laboratory studies of the biochemistry of ancient sediments have given new dimensions to our concept of the age of terrestrial life, while studies of the artificial synthesis of amino acids from inorganic components under a variety of physical and chemical conditions, besides shedding new light on the probable modes of the origin of life on earth and the nature of its chemical environments, have also carried important theoretical impli- cations for our notions about the existence of life on other planets.

At the Department of Plant Biology, work on photosynthesis has pro- duced suggestive insights about that critical step which, with all the research that has been brought to bear for the last half-century, still eludes our understanding — the initial process by which the energy of light is used in the fixation of carbon dioxide. It has brought suggestions, too, about that further mystery, still elusive, of what it is about the chloroplast that enables it alone, when intact, to bring this about, whereas extracted chlorophyll itself will not. And in that Department, too, investigations of many years' duration have illuminated the detailed bases of plant evolution — of the roles of mutation and selection, of the development of ecological races and of speciation — and have revealed the often enormously complex and exquisitely coordinated detail of the evolutionary patterns they compose, at the levels both of form and of physiological function.

In three laboratories of the Institution — the Department of Terrestrial Magnetism, the Department of Embryology, and the Department of Genetics at Cold Spring Harbor — investigations of cellular metabolism and development, of cellular differentiation, and of the mechanisms of heredity at the molecular level have brought striking new knowledge of the detailed ways in which the materials of heredity and of development interact at the level of the cell nucleus and of its cytoplasm, at the level of the germinal cell and of the body cell of the plant or animal, at the level of differentiation and development of the individual organism, and at the level of its heredity.

Such discoveries and results are but scattered samples taken from a rich

10 CARNEGIE INSTITUTION OF WASHINGTON

matrix of sixty years of Institution work. But they are fair examples of its most typical fruit — the truest product of the philosophy in which it was founded and through which it lives. It may well be said that all else is in one sense by-product.

In the seventh decade of the twentieth century, it is hard to recast the scientific and technical America in which the Carnegie Institution was founded in 1902. In the America of 1902, few if any corporations in the United States could boast over sixty thousand stockholders. The American Telephone and Telegraph Company, as example, admitted to less than eight thousand. A third of all the manufactured products of the country were produced by partnerships or by individual proprietors. Speech had been transmitted by wireless, but the Fleming valve was still to be produced, and the first audion was not to be developed for eight more years. The first aerial flight, the twelve-second achievement of Orville Wright at Kitty Hawk, was not to occur until the following year. The earliest motion picture to tell a connected story, The Great Train Robbery, was yet to be produced. A large proportion of such great technical industries of today as the movie and the aircraft industries had not been born, and even the technical prin- ciples underlying the television industry were not yet remotely conceived.

The independent industrial laboratory had been pioneered some years earlier by the Arthur D. Little Company, but the concept of such a labora- tory within an industry had just been formulated and put into practice with the establishing of the General Electric research laboratory in 1901 and of that of the du Pont Company in the same year the Institution was founded. Of all the great complex of industrial laboratories that were to transform the nature of American industrial science and technology in the twentieth century, not one other had yet appeared.

For the scope of science in that day, it is worth noting that in genetics it was only two years before that the work of Gregor Mendel had been rediscovered and its significance truly appreciated by Hugo de Vries and Correns and von Tschermak-Seysenegg. The very notion that some genetic characteristics can be dealt with in crosses in numerical ratios was still unfamiliar, while ideas of genetic linkage and dominance, or the notion of the linear array of genes, was still almost a decade away. Indeed, there was no proper science of genetics at all, and the word gene itself had yet to be coined. In astronomy, it is probably fair to say that the entire known universe was thought to lie within our own Galaxy. By contrast, within the range of the two-hundred-inch Hale telescope today lie perhaps a thousand million such galaxies.

REPORT OF THE PRESIDENT H

Only seven years before the Institution was established, Wilhelm Roentgen had given the first demonstration of the X rays that bear his name, and the first Nobel award in science had gone to him for that dis- covery only a year before the founding of the Institution. The electron had been discovered by J. J. Thomson but five years earlier, and radium and thorium had been isolated by the Curies only four years before. Max Planck had advanced the quantum theory in the year preceding the founding of the Institution. And the special theory of relativity was not to appear for three more years. The Institution was five years old when the first Nobel award in science to be made in the United States came to Albert Michelson.

In the world of technology, plastics, synthetic fibers, vitamins, anti- biotics, all were unknown. And in practical medicine, it is striking that the national death rate from influenza and pneumonia was reckoned at one hundred and eighty-two per one hundred thousand of the population — a figure to be reduced to thirty-nine forty-eight years later. In the same period deaths from scarlet fever fell from more than eleven per thousand to a total of sixty-eight for the entire country. It is worth recalling that, when Lord Lister, scientific disciple of Pasteur to whom the whole concept of antisepsis and sterilization in medical practice may be said to have been due, died in 1912, the Institution was already completing its first decade. Such was the world scene of science and technology within which the Institution took its place.

In 1902 science and technology were already familiar concerns within the federal government. They were indeed concerns as old as the nation itself. It was Thomas Jefferson who as Secretary of State in 1790 submitted a "Report ... on the Subject of Establishing the Uniformity of the Weights, Measures, and Coins of the United States," and who, upon recommendation of the American Philosophical Society, transmitted to the Congress a proposal for the establishment of a United States Coast Survey, which was set up within the Treasury Department seventeen years later. And it was John Quincy Adams, when he was Secretary of State, who personally prepared for the Congress a similar report upon weights and measures. It was Adams, too, who led the fight to accept the bequest from James Smithson, who had died in 1829, to found the organization that was to grow to the Smithsonian Institution of today. The establishment of the Depart- ment of Agriculture dated from Civil War days, contemporary with the passage of the Morrill Act. So also did the National Academy of Sciences, from whose recommendations, somewhat later, were to follow the Geo- logical Survey and the Weather Bureau.

12 CARNEGIE INSTITUTION OF WASHINGTON

These early involvements of the federal government in science and technology, however, gave little hint of the massive and commanding role it would play on the national scene in little more than half a century. Even at the end of the fourth decade of the twentieth century the total federal research program is estimated to have cost annually only about one hundred million dollars — less than the annual budget for the National Science Foundation alone in 1962. Twenty years later, however, yearly federal expenditures for research and development had grown to over a billion dollars out of a total estimated national commitment of about three billion. By 1960 the national total had climbed to fourteen billion dollars or more, of which the federal government supplied some nine billion. Today it may have reached sixteen to eighteen billion. The budget of the National Science Foundation for scientific research and related activities as submitted to the Congress for 1963 will total one hundred and sixty-five million dollars, while the Department of Defense is expected to spend about seven billion dollars on research and development, the National Aeronautics and Space Admin- istration about two and one-half billion, the Atomic Energy Commission approximately another one and one-half billion. The total government funds spent in research and development in 1963 are expected to reach almost twelve and one-half billion dollars, of which expenditures for research alone may attain to one and one-half billion dollars, as compared with approxi- mately one billion for the present year.

It has been calculated that the total funds expended for research and development in the United States over the past decade have increased at approximately fifteen per cent per year, leading to a doubling of volume every five years. If the present rate of increase of our expenditures in the field were to continue, indeed, our projected monetary support of research and development in their current definition could formally exceed our total governmental budget before 1975, and could exceed our gross national product before the end of the century — a reflection, however hypothetical, that vividly illuminates the scientific and technical dynamism and the scientific and technical problems with which we live. How different is this scene from that upon which the Institution entered !

The implications of this astonishing vista are many. One is the degree to which, with almost explosive suddenness since World War II, science and technology have been universally recognized as of major national concern. Another, of course, reflects the depth and intensity of technological compe- tition in the world and our own needs in national defense. A third mirrors both the rate of population growth and, most pointedly, the growth of wealth in the United States. And the climates in which these expenditures on both the private and the public fronts have taken place and the govern- mental patterns through which they are effected in the public sector —

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patterns at present in perhaps their most active phases of evolution and of adjustment — make a compelling chapter in the history of development both of American scientific enterprise and awareness and of American political institutions, and reveal much about their nature.

All these factors — the vast increase in the volume of our scientific and technical resources, in human and in monetary terms and in terms of scientific and technical facilities, the pressing demands of overriding national objectives, economic and military, the consequent larger and larger partici- pation of federal resources in the total funding of the national research and more especially of the national technical effort — have, not unnaturally, had profound impacts on our thinking about science generally. Bit by bit they may have led to some subtle changes, perhaps well-nigh unconscious ones, in our conception of the ways in which, typically, the frontiers of truly new scientific knowledge are pushed back. This evolution could carry implica- tions grave enough to warrant serious thought.

In all the years of American scientific research, from the times of Josiah Willard Gibbs to those of the second world war, we were accustomed to think of the great advances in scientific thought, of the initiation of its great new directions, as being predominantly the product of individual genius, working in environments which, however modest, and in part perhaps because of that very modesty, were especially adapted for flexi- bility, for absence of constraint, for a maximum of freedom in concept and in execution. We thought of the outstanding scientific conquest as typically an achievement of extraordinary brilliance, originality, and insight in individual innovation, giving significant new dimensions to its time, and ideally climaxing a career of unfettered scholarship. We did not particularly conceive research in this sense as the composite product of large numbers of men working in numerous and highly organized groups.

Since the second world war, however, following the spectacular demon- strations of technical conquest wrought by great organizations, of which the Manhattan Project was but the forerunner, we have sometimes been inclined by analogy to conceive of pioneering research for basically new ideas in rather similar terms — inclined, perhaps, to more than half believe that in the contemporary world it too may require such teams. It is then only logical to reason that if, at this stage of the world's scientific develop- ment, pioneering scientific research critically depends upon the large-scale efforts of highly organized and massively implemented teams, its effective- ness may be roughly proportionate to the material resources bestowed upon it — and that cost and magnitude themselves may provide an important index of scientific significance. We have even been tempted at times to imagine that the speed and effectiveness with which new scientific frontiers are breached may be a simple function of numbers of men and rates of

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expenditure, and to expect that the attainment of new scientific vision in an area of basic research may be accelerated in direct proportion to the size of teams and the amounts of money committed to the search.

This philosophy, so directly derived from the demonstrated course of practical achievement, appeals especially to that keen pragmatic instinct that has run like a golden thread through all the fabric of our development as a nation, and to the genius for organization which has so long been one of our most pronounced national characteristics. Nor is there lack of evidence that at first sight seems to confirm the idea. It is patent today that the physical equipment required on the frontiers of research in many of the sciences, especially those of the greatest conceptual maturity, is massive, complex, and expensive, and requires the collaboration of sizable teams in designing it, in manipulating it, and in gathering data with it if truly new information is to be obtained. The productiveness of research in many such fields since men and money have made possible the design of powerful new tools and massive teams have been assembled to operate them gives vivid testimony to how powerful, and indeed how indispensable, resources of this kind may be in some of the most highly developed fields of science.

Yet in a deeper sense this judgment may harbor a considerable, and sometimes a positively dangerous, misconception, especially when it is assumed that great teams and high costs are prerequisites for the setting of new directions in scientific thought. A part of that misconception doubtless stems from a failure to demark sufficiently two general approaches in research, which, though they are complementary and often intergrade, yet have certain characteristics and pose certain requirements that are quite distinct. In one the basic ends of the investigation are generally evident, if not wholly clear in detail, at or near its beginning. The preeminent challenge to the investigator is to chart the road toward his goal — mapping it, projecting it, building it, all that it may approach a citadel already at least dimly visible on the horizon. The other general kind of research may begin without specific ends or, indeed, without consciously conceived objectives of any kind. Its driving motive is likely to be pure curiosity, the winning from Nature of deeply new knowledge, of knowledge won wholly for its own sake. The talents and the training demanded by these two kinds of research, and the difficulty of the scientific challenges posed by each, are often much the same. At one end of a spectrum of research they intergrade, and any distinction attempted between them becomes formal and unreal. At their extremes, however, the challenges they present are undoubtedly quite different, often to be met in widely divergent ways. Above all, whereas research programs of the first kind can frequently be visualized in a general way ahead of time, and so planned intelligently, the same is rarely true in the second type of research. A very large share of the concerns of such a

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great team effort as was involved in the program of the Manhattan Project, for instance, fell into the former category. The deeply underlying theoretical knowledge, the unexpected and radically new ideas about Nature, on which the whole program of the Project was based and on which it turned, had been achieved by investigators like Meitner and Hahn and Strassmann in Europe in 1938, by such individuals as Rutherford and his colleagues at Cambridge in 1914. They had been won through research of the second kind, conducted by a very few gifted scientists working in the settings we have traditionally visualized as consonant with the finest of individual creative effort.

It is no accident that today we sometimes make these distinctions less clearly than we might. At a very deep level it may be a consequence of our peculiar history and circumstances. Throughout our earlier years as a technically developing nation we were able to rely on the older countries of Europe for basic ideas on which to build our applications as implicitly, and often as unconsciously, as we relied upon the British navy for the protection of our seas. It was both natural and adaptive that the kind of scientific and technical contributions at which we early became most adept and developed most highly, and to which perhaps we initially attached greatest attention and attributed greatest value, should have involved the brilliantly organ- ized, the meticulously careful development, often undertaken on the boldest and most breathtaking scale, of basic ideas that had been conceived abroad. Today such ideas are much more often drawn from our own resources. But historically our first attachment was to their execution rather than to their generation. And so it is not surprising that we sometimes fail to distinguish innovation from execution, and have not always recognized the limitations within which we can extrapolate experience from one kind of activity to the other.

But there is more to the matter than this. For it is demonstrably true that gains in our knowledge of Nature as new and fundamental and unex- pected as any in the world can come, unbidden, from the investigations of great teams for research and development in many areas. As our resources for team research grow in the coming years, we can properly expect the rate at which such new knowledge is revealed to increase also — if not proportionately, at least very substantially. And so we should not fail to ask an implied question of great importance. The philosophy that envisaged the environment of brilliant, original, unfettered individual research as the milieu in which the great new directions of scientific thought were born and nourished, the philosophy which has had such confirmation in recent scientific history, was itself developed in the days of scarcity in science —

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scarcity not only of material wealth, but especially scarcity of scientific workers. Now we live and work in a nation committed to an unparalleled rate of growth in the material resources for research, and in a world in which perhaps eighty per cent of all the scientists who have ever lived are our contemporaries. Is it possible that the philosophy itself was adjusted to the needs of other times ; that it is not relevant to an era of plenty? May it actually be true today not only that major advances in new knowledge, the setting of radically new scientific directions, can be achieved in the environ- ment of great and highly organized research teams, but also that, in practice, such environments are indeed essential, or, at any rate, the most favorable, to the process? Is it possible that we are witness to a profound revolution in the very character of research itself? Is it possible that the small and mobile groups to which we earlier looked for some of the most significant scientific innovations, the groups which in the past characteristically had an influence on scientific progress out of all proportion to their numbers or their social cost, can no longer in our day provide such significant approaches to the unknown?

Such a radical query, of course, bears profoundly on the whole philosophy of research. It is far more than a practical question. It touches some of the deepest wellsprings of scientific faith. It touches belief in the very nature and effectiveness of the individual search for truth in our time. In subtle ways it touches on the nature of scientific truth itself. It is an important question for the Carnegie Institution, deeply committed to the faith that the distinguished, unfettered individual can bring unique gifts to his society, and deeply committed, too, to belief in the uniqueness and the im- portance of the influence which a community of independent scholars can exercise on scientific progress.

For a question of such magnitude and gravity, abstract analysis will not suffice. Contemporary evidence alone can give convincing answers. Have the recent great advances in our knowledge of the universe and of our own more immediate environment, the original ideas of scientific stature achieved in the last few years which promise to open truly novel avenues of thought for the future — have these been necessarily, or even primarily, associated with the massive programs of great teams? Or do the basic contributions of small and mobile research groups continue in our day to have their old significance?

Such an abundance of evidence springs to mind, provided by striking advances no more than a half-dozen years old, in so many regions of scientific inquiry, that its very selection poses a problem and must necessarily be arbitrary. But three outstanding areas of recent investigation are particu-

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larly interesting to consider from this standpoint, because their environ- ments and circumstances span such an extraordinary range of magnitude and character and form.

The first example may comprehend that immense complex of research and development dedicated to the placing of man in outer space and ultimately on the moon or on neighboring planets, its present great achievements in our country vividly symbolized by the voyages of Shepard and of Grissom, of Carpenter, Glenn, and Schirra. The second is of quite a different kind. It involves an achievement in astronomy of the year just past which in the stag- gering distances with which it deals emphasizes anew what a thin terrestrial shell is the outer space so far entered by man. It is the identification of what has proved to be by far the most remote celestial object ever discovered in the heavens — an object certainly billions of light years distant from us — and the measurement of the redshift of its spectrum. The third selected area of advance may in some ways be the most profound of all, though it is far from the best known. It includes the experimental evidence so brilliantly obtained in the last few years, and the reasoning directing the search for it, indicating beyond reasonable doubt that the information governing the inheritance of all the qualities of living things is structurally graven on the chromosomes within their germ cells in the form of a genuine code. It includes, as a climax, the demonstration of the general nature of that code, which the year just past has witnessed. These findings may well mark the greatest single ad- vance in genetics since the demonstration five decades ago that the genes of heredity lie in the chromosomes in a linear array.

These three advances in natural knowledge bear much resemblance in certain fundamental qualities. All have won important and striking new knowledge. In all of them, the research for that knowledge has included a variety of scientific disciplines apparently far removed from the main concern — in the case of the third as far removed as crystallography seems to be from conventional genetics. Profoundly new directions of thought have resulted from all three. Possibly the third has produced the most thoroughly revolutionary new insights. The first has brought a sense of liberating con- quest and a wealth of first-hand information about regions known hitherto only palely and at second hand.

But in many features of the modes and environments of research char- acterizing them, the three examples diverge about as much as scientific activities can differ. The contrast is particularly vivid when cast in terms of the parameters under special consideration: the relative size of the efforts, the sheer volume of human and material sources brought to bear, the kinds and degrees of organization. The enormous magnitude of the space program and the tremendous cooperative efforts currently involved in its prosecution and planned for the future need little emphasis. In this respect, indeed,

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Project Apollo is much in the tradition of a Manhattan Project, though yet bolder in both variety and scale. It is estimated that by the close of the budget for 1963 the National Aeronautics and Space Administration will have spent more than four thousand millions of dollars for the conduct of research and development. For research facilities alone it will have expended more than eight hundred and twenty millions. Behind the great individuals who have manned the space vehicles, and have recorded and analyzed the data of research, and who will do so in the future, lie the years of develop- ment on a scale of unprecedented magnitude and the immense organizations required for its successful prosecution. Behind the fashioning of the tools the final explorers command lie combinations of highly specialized dis- ciplines and intricate techniques of the most varied kind — chemical, elec- tronic, mechanical — ranging from the arts of propulsion engineering to those of miniaturization. It is interesting to notice in this connection that the cast of the effort at present is, as it perforce must be, importantly oriented about the design and use of tools. In considerable measure it is basically an engineering effort — perhaps the most exciting and compelling engineering effort of this century.

Shortly after the second world war, when instruments of radio detection were being put to a new use in the service of astronomy, several surveys of the skies were undertaken to detect and locate the positions of celestial bodies that were emitters of radio waves. The equipment then available, however, was relatively poor in both resolution and accuracy. It could not effectively complement the far more precise tools of optical astronomy. Resolution and precision were often too low to permit a reliable identifica- tion of radio sources with corresponding objects observed optically, though sometimes they were suspected to be the same. As the techniques of radio astronomy sharpened, however, as larger dishes were built and manned and put into use, both penetration and resolving power improved greatly. At the radio observatory of the Cavendish Laboratory in England and at the observatory of the California Institute of Technology at Bishop in the Owens Valley, instruments of outstanding capacity were built. During 1959 and 1960 two fresh surveys of the skies were undertaken with them: in Cambridge at 169 and 189 centimeters, in California at about a sixth that wavelength (31.2 cm). In the course of these surveys the celestial positions of certain emitters of radio waves were determined with a new precision. So precise was the location of one of these objects, indeed, that the two- hundred-inch Hale telescope could be brought to bear upon it. The peculiar color characteristics of the object suggested that it might include a pair of galaxies in collision, and so might be expected to have one or more emission

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lines in its spectrum. And so it happened that a prescient astronomer of the Mount Wilson and Palomar Observatories was able to obtain two spectra of the visible light from this source and to measure the degree of redshift in them. At the same time another observer, obtaining multicolor photometric observations of two of the fainter galaxies of the same cluster and construct- ing their curves of continuous emission, confirmed this measurement of red- shift. It corresponded to a recession velocity of nearly half the speed of light. This heavenly body defines a new boundary for the universe compre- hended within human ken. It marks by far the most searching probe into unplumbed reaches of space that the mind and hand of man have yet accomplished, ranging certainly to the order of several billion light years. When it is recalled that a single light year amounts to almost six million million miles — about sixty-three thousand times the distance of our own world from the sun — it makes the orbits of earth satellites, spectacular as they are, yet appear as comparatively near-neighborhood adventures.

Perhaps the greatest ultimate significance of this achievement will lie in the contribution it can make to our ideas about the basic nature of the universe. Indeed, this newly determined point of distance, so far beyond any other yet obtained, has already offered suggestive evidence on the great question of whether our universe is a continuously expanding one, or a universe in which the continuous creation and destruction of matter stand in equilibrium, or whether the universe in fact may experience alternate expansion and contraction extending over astronomic periods of time.

In sharp contrast to the first example, the planning of these observations, their confirmation, and the deductions from them were not the work of great teams of highly coordinated technical workers. These were the fruits of observations and calculations made by a few individuals laboring in relative solitude, the fruits of work of a relative handful of gifted astronomers. Perhaps never in science has the work of individuals been more clearly identifiable. The contrast with the first example is sharp.

Yet behind this classical achievement of gifted individuals lay many decades of research and engineering focused on the design of the powerful modern tools of optical and radio astronomy. Without them the achieve- ment itself would have been quite impossible. These tools, like those in- volved in the space effort, were the products of hands and minds and toil in literally hundreds of specialized skills. And it was not skill and art that alone were brought to bear, but with them the magnificent resources of intellect and materials and time and research that gave them scope and effectiveness. The achievement itself dramatically underlines how significant and how essential the gifted and untrammeled individual investigator is today on some of the most advanced frontiers of the physical sciences. It was pri- marily focused on the gathering and the interpretation of information about

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nature, not on the design of tools. Yet its success depended in turn on a panoply of instruments brought to perfection in other times and other places, the development of which had required a structure of science and technology of whose cumulative magnitude and scope no scientist of an earlier generation could have had the faintest dream.

The third example embodies yet a different pattern. It would be hard to imagine a more fundamental or more sweeping discovery than one elucidat- ing, at a deeper level than had hitherto been imagined, the manner in which the information governing all the qualities of inheritance may be recorded and stored in the chromosomes of plants and animals and men — stored with such extraordinary effectiveness and such enduring stability that there are organisms living today whose hereditary characteristics have been main- tained more durably than the very rocks within whose strata the fossils of their remote ancestors are preserved. Yet in terms of magnitude the human and the material resources committed to that search, by comparison with the preceding illustrations, have been positively minuscule.

In 1953 Linus Pauling and Robert Brainard Corey at the California Institute of Technology suggested that the molecular structure of the unit of heredity, the "molecule" of deoxyribonucleic acid, might consist of chains of polynucleotides intertwined in the form of a helix, with four characteristic bases, the purines adenine and guanine and the pyrimidines thymine and cytosine, attached to them and projecting outward, while phosphate groups were oriented to the center. There were features of this model which con- flicted with experimental evidence, notably that it was hard to reconcile the fact that DNA is an acid with the existence of bases lying, as it were, on the outside of the molecule. But the model involved one very great idea which, though it was not widely credible in terms of that particular construction, yet was to prove fundamental to all further thinking on the matter. It was the idea that the biological specificity of the unit of DNA, on which its power of determining inheritance must rest, must inhere in the sequence of occurrence of these bases along the molecular chain and the suggestion that the periodic distances at which these bases occur might be of the right order to permit them to order the sequence of amino acids in the construction of a protein. This was a most important foundation upon which to rear what would prove a truly extraordinary arch of reasoning. But for long even the idea that the nucleic acid structure could be locally specific was resisted. Until that idea had been widely accepted, its more detailed consequence could hardly gain effective credence. Both these developments were made possible by a second great idea, which might be likened to a keystone of the arch.

This critical idea was provided by J. D. Watson when, in a flash of insight

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reminiscent of Kekule's vision of the structure of the benzene molecule that came to him in a London bus almost a hundred years ago, he imagined the consequences of, in effect, turning the model inside out, pointing the bases inward, and pairing the purine molecules with the smaller pyrimidines. Highly significant correspondences with nature were achieved by this remarkable insight. The first and fundamental rule of the composition of deoxyribonucleic acid, namely that it incorporates purines and pyrimidines in equal ratio, was given a rational basis. And the contradiction between the acidic nature of DNA and its presumed outwardly pointing bases, which had plagued the model of Pauling and Corey, was resolved. But there were impressive difficulties to be met also. The idea that the bases were outward- pointing had not resulted simply from neglecting the alternative that they might point inward. That possibility, indeed, had been carefully examined in formulating the earlier model. But it had been concluded that such a structure was not possible. For the new model to be convincing, the physical possibility of such an arrangement had to be demonstrated, and the details of the linkages between the purines and pyrimidines had to be worked out — formidable tasks requiring concepts and techniques familiar to those dealing with the structure of crystals.

And so it was that, also in 1953, Watson and F. H. C. Crick, working in the Molecular Biology Unit of the British Medical Research Council adjacent to the Cavendish Laboratory at Cambridge, announced their brilliant hypothesis of the structure of the unit of heredity, of the "molecule" of deoxyribonucleic acid, as a pair of "ribbons" wound in the form of a double helix around a common axis and linked by the four bases, the purines adenine and guanine and the pyrimidines thymine and cytosine, paired in a highly specific fashion. The model of Pauling and Corey had suggested that the bases could not be packed in the center of the molecule. The new model proved that indeed they could, and from that demonstration came perhaps the most significant idea in the whole chain — the concept of base pairing itself, and with it the associated and important notion that a maximum of four kinds of base pairs could be involved. The beauty and credibility of the model gave firmness and emphasis to the earlier idea that the biological specificity of the unit of heredity must derive in large measure from the ordering of the pairs of bases along the chain of the deoxyribonucleic acid.

All together, three biological consequences stemmed directly from the model, which must rank among the most important advances of our age in the understanding of the fundamental nature of earthly life. First, the model allowed the extraordinary phenomenon of the replication of the genetic pattern which occurs at every division of every living cell — the mechanism fundamental to the very process of the growth and multiplication of life on earth — to be understood consistently for the first time. Second, the nature

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of the phenomenon of the sudden changes in inheritance which we call mutation, intensively studied since the days of de Vries but never under- stood in their fundamental molecular mechanisms, now for the first time became comprehensible at that level, in terms of known changes in bases which could result in alterations of their sequence to produce such changes. Third, and greatest of all, perhaps, was the full rationalization of the key concept that biological specificity in inheritance must in large part derive from the sequential ordering of the bases in the nucleic acids.

This third great consequence was to lead to a scientific vision of new and unexpected dimensions. That vista was provided by the idea that genetic information might in fact be coded in the DNA molecule in the form of a linear message for which the four permissible combinations of bases might serve as alphabet, in a manner, indeed, reminiscent of the coding of a message on the punched tape of a computer. This radical concept was first examined in detail by the astrophysicist Gamow in 1954. Although the precise form of the code suggested at that time has since proved incorrect, the basic idea has become established as one of the great theoretical ad- vances in our view of the nature of the living world. And so was posed the pointed question: if such a code exists, what is its specific nature?

It is that question which theoretical and experimental work of the past two years has done much to answer. An important share of the answer, like the original question, has come once again from the laboratory of the Unit for Molecular Biology at Cambridge ; other critical parts have followed from several American university laboratories, from the National Institutes of Health, from the Carnegie Institution of Washington. Suffice it to say that preponderant evidence suggests that the code employs words containing very few "letters," probably not more than three.

A virus may include within its single chromosome something of the order of a hundred thousand base pairs. A billion pairs of bases may be included within the total store of information of our own chromosomes. It is a startling concept that if the DNA strands from all the cells in a single human body were uncoiled their total length might well span the solar system. There is ample opportunity for diversity in the ways that the elements of the code can be combined.

With this conceptual advance, carrying the implication that one of the basic challenges offered by the problem of heredity might lie, in effect, in the decoding of a script, progress in meeting that challenge has come with remarkable speed. What may well prove to be a Rosetta stone has been provided by the development of methods of accomplishing protein synthesis in cell-free systems under the influence of artificial ribonucleic acids com- posed of only two bases in known ratios and therefore containing specified code words in known frequencies. The composition of the resulting protein

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should yield the key to code " letters" in terms of the ratios of specific amino acids corresponding to them. Another highly promising approach involves techniques for investigating the coupling between the base-pair patterns of the deoxyribonucleic acid of an organism and the "messenger RNA" of related forms, which may differ in their coding only in relatively minor, but specific and determinable, particulars. The current year sees work of this kind at a peak of activity. With wing-swift speed, a whole new area in our understanding of the basic mechanisms of heredity at the molecular level is being exploited.

Here, then, are three genuinely great advances marking the technical and scientific progress of the last three years. In a profound sense all three are typical of their age, and, for a variety of reasons, could not have occurred at any earlier time. Obviously neither space exploration nor the astronomical investigations of the new "edge of the universe" now within our ken could have been achieved with the tools of any other era. The peculiar modernity of the third example involves especially a yet different circumstance. For the very idea that the information of inheritance may be recorded as a code is peculiarly consonant with our age — perhaps so characteristic that it should be treated with a caution doubled by this very fact. In the nascence of primitive biological thought fire was a living thing, dangerous and bright, and the expression "vital fires within us" remains to remind us how much we once thought of life as the "inhabiting property" of something that was obviously dynamically alive. In an age when the frontiers of engineering exploration concerned pumps and hydraulics the mechanism of the circula- tion of the blood was a fascinating and fertile subject of physiological speculation and of physiological research. For the age of Descartes, strings and pulleys provided compelling images for the mechanisms of life, and images of clockwork for the mind. In the early nineteenth century, domi- nated by the vision of steam power engineering, energy transformations seemed among the most important aspects of life, and the rise of large-scale electrical power engineering in the latter part of the nineteenth and the early twentieth century reinforced the vision. Then, in our own era, with its emphasis on small-current engineering and the modulated control of gigantic mechanical and electrical processes, the aspects of living processes included under the rubric of Cybernetics have occupied a center of the stage. Studies of those fascinating properties of living systems involving, in all their varied and exquisitely elaborate mechanisms, the maintenance of homeostasis, the preservation of balance in dynamic systems, have held a special attraction for our time. And in our immediate day, when communication of new orders of content and of speed, and with it the massive processing of information,

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so dominates our lives, when we are inevitably so much concerned with the coding of information and the unraveling of such codes, it is scarcely surprising that a natural process operating upon those principles, which has evidently been central to the evolution of all life, as no doubt it was also in its origin, should only now have so powerfully focused our attention as to be on the threshold of solution. It follows, too, that, just as each of the earlier interpretations of living processes subsequently gave central place to its successor but left the residue of its own unalterable truth to contribute permanently to our basic understanding, we must be prepared to accept — and indeed to welcome — the same fate for the concept of genetic coding.

The likenesses uniting these three examples, then, lie deep. It would be hard to select the most significant among them, though in the achievement of particular new insights the second and especially the third may pre- dominate. What now of the parameters of scale, of magnitude of the re- sources committed, of the extent of organization of the work, as criteria of its significance? Here it would be difficult to imagine wider contrasts.

At every point in the extraordinary conceptual development that marks the third example, the commitment to it in terms of numbers of workers, in terms of material resources, was extraordinarily modest. The Unit for Molecular Biology of the Medical Research Council at Cambridge began with two crystallographers. Ten years later, when its revolutionary dis- coveries were well launched, it numbered perhaps a dozen workers and was housed in a temporary building behind the Cavendish Laboratory and in various University rooms — a very minimum of space. It was, indeed, superbly instrumented for its task. But such instrumentation was in- credibly modest in both mass and cost compared with that required in either of the other fields. In that free and flexible atmosphere, built about the largely unfettered efforts of a few gifted individuals working within a minimum of formal organization, have been made some of the most im- portant advances in man's concept of his world and of himself possible to the twentieth century. It is striking to compare this situation with that in which the exploration of space must go forward.

This, then, is the character of the contemporary evidence. Such contrasts of size and structure and organization in the modes of some of the most significant assaults on the frontiers of natural knowledge in this decade strongly suggest that these parameters, broadly considered, bear little direct relation to their scientific significance. They inspire compelling re- flections about the continuing effectiveness, in our own day, of the scale and

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the pattern and the philosophy of research to which the Carnegie Institution is so deeply committed. It seems abundantly clear that the essential qualities and requirements of inquiry at the very frontiers of man's knowledge of his universe do not now, and in all probability will not in the foreseeable future, differ significantly from those of our classical scientific past. Such inquiry will surely continue to bear the unmistakable stamp of the gifted and un- trammeled individual, whatever may be the scale of resources, in knowledge, in tools, in human and material support, which he may require.

Bronowski has pointed out that perhaps the most fundamental discovery of the scientific age was that Nature was to be approached and won, not by attempting to outwit her by magic, as many a medieval alchemist had imagined reflecting a prevailing climate of his time, but rather by discover- ing the true quality of natural laws and taking care to work within them. It is easy to forget how tremendous was that change of view, how much of trial and vision was comprehended within Newton's simple admonition that "science must be kept free from occult influences." The atmosphere of true research is still as it was when that great advance of philosophy was made, still the atmosphere in which, as Lionel Trilling has recalled, Faraday re- fused to be called physicist, holding the term too narrowly imprisoning a chamber for his life's commitment. These are the dimensions, whatever be the nature of the structures in which they are embedded, which still evoke the great advances of today.

In the central context of discovery, it seems clear that the magnitude and organization of a research effort may be the least meaningful of parameters in any fundamental or enduring sense. One may indeed think of the large and the small research enterprises in our society as essentially symbiotic, each fulfilling its specific role — one more example of the rich diversity by which we live.

The relation, however, is actually more subtle. The responsibility that devolves upon small and mobile groups dedicated to the exploration of new frontiers is clearly greater in our own clay than merely that of one component in a many-hued panoply of research. At least one aspect of the relation is far more serious, and wears a significance which must inevitably sharpen further in the coming years. It is not only important that the small and mobile re- search group be maintained and strengthened to ensure continuing advance along those remote boundaries of natural knowledge so vital to our spiritual as well as to our material well-being. It is not only important be- cause, in such a massive and highly advanced technical and engineering society as our own is today and must even more become tomorrow, the scientific "leverage" of such pioneering groups must inevitably increase. It

26 CARNEGIE INSTITUTION OF WASHINGTON

is a further and a significant truth that, while climates that foster innovation can be maintained in the midst of complex and highly organized technical undertakings, preserving them intact is no common or easy achievement. It requires a particular determination, an extraordinary persistence of vision and pertinacity of will, an unusual sensitivity and skill, to sustain conditions favorable to original, exploratory research on remote and far-flung frontiers of the mind in massive working environments over considerable periods of time, undeflected by all the immediate demands that architecting to known ends in those environments inevitably imposes, in some multiple proportion of intensity to scale. Without the sustaining view that small and mobile groups attaining great discoveries can offer, without their inspiration, the task must become doubly difficult. These circumstances may define for the small and mobile group the most demanding and important of all its functions — the heavy responsibility of the keeper of a vision — the vision of the creating individual.

In the future that responsibility may well become not only wider but yet more challenging. For it is abundantly evident that science and technology, in the world as a whole as well as in our own nation, have entered phases of development in our day so different in scale and complexity from their beginnings — or from what, incidentally, the newly developing nations of the world may confront or may require in their own immediate futures — as to differ essentially in kind. As Pierre Teilhard de Chardin has written with sensitive perception, "The Earth is covering itself not merely by myriads of thinking units, but by a single continuum of thought, and finally forming a functionally single Unit of Thought of planetary dimensions." An important aspect of the qualitative growth of contemporary science, of course, inheres in its essentially additive nature, in the formidable integration of knowledge and of thought characteristic of a pursuit where discoveries in one field may in the span of a few months alter the entire basis against which thinking in very different areas must be projected. Another concerns almost the op- posite situation. The significance of great research is largely measured by the impact of its results over a wide range of frontiers of inquiry, demanding the widest and swiftest communication possible and challenging human intellectual capacities for assimilation and generalization to their limits. But the processes of research bring heavy demands on quite opposite qualities — on extraordinarily detailed knowledge of a single field, on that supreme mastery of all its coordinates down to the most minute, developed over long periods of years, which so often is prerequisite to significant and sustained advance. In the past, science has been able to reconcile these two quite opposite requirements in tolerable fashion. With increase of scale the problem takes on new dimensions.

Science in the last decades has responded to the challenge with enormously increased sophistication, with vastly expanded organization and integration

KEPORT OF THE PRESIDENT 27

of knowledge, with, indeed, quite a new development of recent years, the field of research on research itself. But as science has matured in its modes of cultivating the whole vast field of its thought, as its power has grown to enter and occupy new areas of research in force so soon as the first hint of them appears, these very qualities have brought novel and troubling consequences for the gifted individual, particularly for the gifted young research student just entering upon his life's work, upon whom so much of the future de- pends. As A. B. Pippard, among others, has pointed out dramatically, the legions of investigators can now be mobilized with such speed and effective- ness at a new and attractive breach in the frontier of knowledge that, particularly if the area offers a promise of practical benefit, a green and fertile intellectual valley can be reduced to aridity for the innovator within less than the working life of a generation of young scientists. The conse- quences incident to such swift and locustlike invasions, however effective and profitable they may be for a technical society in the large, can be dis- couraging to vulnerable individuals, and they bear at precisely the points of talent and dedication most precious to us. There can be no more urgent imperative than the creation of opportunity for individuals faced with this dilemma to address themselves once again to wholly new fields of inquiry. This too lies peculiarly in the domain of small and mobile and basically highly uncommitted research groups.

What, in final essence, is the deepest meaning of the scientific way? In the profoundest sense, what is the meaning of the individual human life dedi- cated to it? Within the scientific context, as well as outside it, what, at last, are people for? A generation, perhaps even a decade, ago such a question was all but unasked by most Americans. Certainly it was all but unasked in 1902. Even if put, in that day, it would have appeared to many not only irrelevant but quite possibly sinister. But in a world with a population estimated at nearly three billion and predicted by conservative demog- raphers to reach almost four billion by- 1980 and to attain nearly seven billion by the turn of the century, the question wears quite a different aspect. In our own nation, with a population now over one hundred and seventy million and destined perhaps to reach two hundred and twenty million by 1975, the revolutionary consequences of this flood tide upon every facet of the world we know demand no emphasis. It must profoundly affect every circumstance of our society, of its organization and its function. It must affect the individual's inner view of himself and his conception of his relation to his universe, his understanding and his reach in his own physical world, and much else besides.

The rate of growth of the scientific effort today considerably exceeds that of the population as a whole. Inevitably, it would seem, it must change after

28 CARNEGIE INSTITUTION OF WASHINGTON

two or three more periods of doubling. But in absolute terms it would seem beyond reasonable doubt that the legions of technically trained people in the future will vastly exceed in numbers those now active, even as these in turn so vastly exceed the numbers of only a few decades ago. Great technical and engineering efforts will be ready and available to confer rich meaning on the lives of many. In massive and compelling developmental undertakings op- portunities will continue to be provided to great numbers of active minds to labor for ends not only dramatic, not only economically and socially adap- tive, but as creative and as meaningful in our times as the tasks of the builders of Chartres or of the Parthenon must have been in theirs. Pippard has presciently pointed out that, if the field of technology is to prove sufficiently magnetic to attract first-class intellects to it, opportunities for the dramatic and the spectacular, outlets for the moral impulse to share in socially significant undertakings, the sheer intellectual quality of the under- takings themselves, must provide the motivations. Among the great and challenging technical and engineering undertakings of our time, all three motivations are presented on a scale the world may never have experienced before.

But there will be other scientific workers, too, of other and less specially identifiable tastes and talents, hostages to a more distant future. For them the requirements will be quite different. Perhaps the deepest question the times can pose for them, and as well the most poignant for all man's spirit- ual welfare, will be this. In a society as densely packed, as intricately organized, as highly urbanized, as our own must inevitably become in future years, can small and mobile enclaves of thoughtful and imaginative men and women continue to maintain integrity and distinctive freedom within the greater society? On their ability to do so in the broadest context will depend in no small measure the fate of the individual and of those goals and motivations through which in the past we have lived and taken our national being. In a very real sense their persistence alone can effectively preserve the priceless jewel of the opportunity for quietness and temporary solitude which in our past has been so vital a nursery for individual American greatness as well as for that of our society as a whole. For it is the gifted, unorthodox individual in the laboratory or the study or the walk by the river at twilight who has always brought to us, and must continue to bring to us, all the basic resources by which we live. His position must be guarded and honored and implemented with every resource that we can muster, now and in the future, for he is irreplaceable. This matter too, and all the circum- stances attendant upon it, must be a central and abiding concern through all the coming years for the Carnegie Institution of Washington. As Chaucer said six hundred years ago, so may we today: "Out of the old fields cometh the new corn."

The Year in Review

It is fascinating to compare the Institution of approximately sixty years ago with that of today. There was, of course, very little to report from the first year or two of the Institution's existence, which was spent in a search for profitable lines of endeavor and experiments with organization toward that end. As early as 1904, however, the lines the Institution was to follow for some years were discernible, and the report for the year 1905 (Year Book 4) describes the nature of the Institution's work in nearly all of the broad fields in which it was active during 1961-1962. Some glimpses of these early activities, set alongside typical activities in our several fields for 1961-1962, give a most illuminating view of the progress of the Institution, and indeed of science in the United States.

In 1905 the resources and objectives of the Institution were much more widely dispersed than they are today. The total budget for that year was $586,000, a little more than half of which was allotted to ten " Departments of Investigations" which included the forerunners of all the Institution's present fields except embryology. Among the Departments were several that have since been terminated (Marine Biology, Economics and Sociology, History, Nutrition, and Horticulture). Half of the total budget for the Departments ($302,700) went to the Solar Observatory on Mount Wilson, which was under construction in that year. In addition, 43 individuals or organizations outside the Institution received grants to the sum of $130,625 in the fields of anthropology, archaeology, astronomy, bibliography, botany, chemistry, geology, history, paleontology, philology, phonetics and linguis- tics, physics, and zoology. The Institution also had in 1905 a program of subsidizing outside publications of "meritorious works which would not otherwise be readily printed." Nearly $30,000 was expended in 1905 for this purpose and for the publication of works written within the Institution itself.

By contrast the Institution's budget for 1961-1962 was $2,848,480, all of which was spent upon the six operating Departments that have been maintained in recent years. Except for departmental fellowships the Institution made no outside grants and did not subsidize publication for works written outside the Institution. While a great variety of subjects was

29

30 CARNEGIE INSTITUTION OF WASHINGTON

under investigation within the Institution in 1961-1962, research was under- taken in a better organized and more purposeful manner.

Four of the more promising lines of research, as viewed by the President and Trustees of the Institution in 1905, lay in the work of its Solar Ob- servatory, in its Department of Terrestrial Magnetism, in geophysical re- search, and in biological investigations. With rather remarkable perception the importance of fundamental research in the physical and biological sciences is commented upon in the 1905 report. The Solar Observatory is described as ranking among Institution projects "first in order of cost for initial construction and equipment. This cost, however, is no more than commensurate with the magnitude of the problem attacked. . . ." Of the biological investigations, including those of the Station for Experimental Evolution and the Desert Botanical Laboratory, which was the predecessor of the Department of Plant Biology, the report noted that fundamental research in plant and animal biology "for a series of years can hardly fail to yield results of signal practical and theoretical value."

The Department of Genetics

In our series of "then and now" snapshots it is appropriate

to begin with the Department of Genetics, whose prede- 1905 cessor in 1905 was the Station for Experimental Evolution,

one of the most active parts of the Institution in that

year. Even though the Station for Experimental Evolution at Cold Spring Harbor had been in existence for only a little more than a year, a year of very full activity was reported. Following the inspiration of Hugo de Vries, who had given the dedication lecture at the Station the year before, C. B. Davenport described the long-range objectives of the Station's work. "The factors of evolution are three — variation, inheritance, and adjustment. Studies may be made on any one of these factors or on all three together; as a matter of fact, they can hardly be studied wholly independently. . . . Since studies in inheritance have been relatively neglected. . . our first efforts have been directed primarily toward such studies."1 Already five principal investigators and the Director, Dr. Davenport, had commenced their programs of research.

From a modern point of view the range of the work undertaken was astonishing. It was described as "investigations into inheritance and variability" of plants, insects, and other invertebrates; "investigations upon

1 Year Book 4, p. 87.

REPORT OF THE PRESIDENT 31

aquatic vertebrates"; "studies on inheritance in domesticated animals"; and "investigations into the cytological basis of heredity." Experiments were in progress on eight beetle species, three species of moth, flies, aphids, crickets, bees, and snails (Helix nemoralis). The brown trout and several killifishes (Fundulus sp.) were studied, and the Station experimented with goats, sheep, and cats. During the year George H. Shull became well started on the research which led to his later valuable knowledge of maize re- production. But in 1905 he was searching for suitable material for experi- ment, and had a garden of 81 different species of biennials, perennials, and annuals. Along with this search he conducted a variety of experiments, which included investigation of the inheritance of seed weights in beans (repeating W. Johannsen's experiments) and the vegetative habits of Russian sunflowers (Helianthus annuus) and other species. He had also begun his observation of the characteristics of maize. The particular character chosen for study in 1905 was the number of rows on the maize ear. Although the importance of cytological research was recognized, the year's effort failed to devise even a suitable experiment. The report ob- served, "The results of the last three years confirm the belief in the im- portance of the chromatic material in inheritance. This chromatic material exhibits a bewildering complexity and diversity scarcely less than that of adult organisms."2

It is interesting to find in 1961-1962 two lines of investi- gation which were at a germinal stage in 1905. Experiments 1961-1962 with maize are still productive of fundamental results, and cytological research using flies (now the familiar Drosophila) formed an important part of the departmental program. Thus in one way or another these lines have held some of the departmental attention for more than 56 years.

The approach of the Department in 1961-1962, however, was a vastly different enterprise. In a sense Barbara McClintock's methods of working with maize genes are lineal descendants of the variation and inheritance techniques that Shull was commencing to pioneer by counting rows of kernels on ears. But in Dr. McClintock's hands these methods have become highly sensitive and one of the sharpest tools in modern genetics. She has made them a match for other sharp new tools heavily dependent on chemistry and physics. For more than a dozen years she has been interested in the elements associated with genes that activate, control, suppress, or regulate genie action. Her work during these years has revealed the presence in maize of two controlling systems, an Activator (Ac) system, whose pres- ence or absence is associated with the appearance or nonappearance of mutations of a particular gene, and the Suppressor-mutator system (Spra),

2 Year Book 4, P- 94.

32 CARNEGIE INSTITUTION OF WASHINGTON

which causes a varied expression of the action of a single gene as observed in somatic cells. In her research this observation has been associated especially with the appearance of the reddish-blue pigment anthocyanin. Depending on its phase, the Suppressor-mutator element may either inhibit or activate the gene expression which results in the formation of antho- cyanin in maize leaves or kernels.

A second theme of Dr. McClintock's work through these years has been a search for evidence that even the fine structure of inheritance is basically similar for all forms of life. In a much more general way Davenport and others started with the same hypothesis at the Station for Experimental Evolution, attempting to observe genetic expression in many forms of life. Dr. McClintock's first experimental evidence on the similarity of operation of genie control elements in different forms of life was reported in 1950. 3 In that year she observed, " Because the same types of mutability as those observed in maize have been described for a wide variety of organisms, it is probable that the same events, involving the same chromosome materials, may occur in all organisms.4

During the year 1961-1962 Dr. McClintock continued to examine the parallels between the gene-control systems in maize and bacteria. She observes in her report that both organisms have gene-control systems composed of an " operator" element directly controlling genie activity ad- jacent to the structural gene and a "regulator" element acting upon the operator element. Other investigators have shown that the position of the regulator element on the bacterial chromosome may differ for individual systems.5 It may be near to or removed from the locus of the operator element. Dr. McClintock's work during the year confirmed her hypothesis that there is a high probability that genie control systems in maize and bacteria act in similar fashion. She concludes her report by stating that her findings "are sufficiently extensive to leave no doubt that a two-element system of control of gene action, composed of an operator element at the locus of the gene and a regulator element located elsewhere, may arise at a gene locus that initially carried the regulator of the system." It would appear that one more link has thus been added to the gradually extending chain of evidence on basic similarities for many forms of life at the cellular level.

A second field of departmental interest in 1905 survived to 1961-1962. This was the application of cytology to genetics, which was considered, but only futilely explored, in 1905. Indeed, successful development of this field

3 Proceedings of the National Academy of Sciences, 36, 344-355, 1950.

4 Year Book 49, p. 165, 1950.

6 F. Jacob and J. Monod, On the regulation of gene activity, Cold Spring Harbor Symposia on Quantitative Biology, 26, 193-209, 394-395, 1961, presented completely for the first time evidence on the operator and regulator elements in bacteria.

REPORT OF THE PRESIDENT 33

actually was postponed for more than 15 years after 1905, when in the 1920's the work of John Belling finally laid the foundations for modern cytogenetics. This work was continued in 1961-1962 in the research of Berwind P. Kaufmann, Helen Gay, Margaret McDonald, and their associ- ates. The general objectives of the group bore some resemblance to the crudely stated convictions about the importance of cytology in the 1905 report. The group continued its work of nearly two decades, charting the changes occurring in the organization of chromosomes and cytoplasmic organelles as cells in higher organisms grow and differentiate. Their methods, however, were a world apart from those of 1905, including as they did electron microscopy, fluorescent microscopy, enzyme chemistry, and bio- chemically specific stains. In addition, they had at their disposal the vast knowledge that has accumulated over 40 years on the genetic characteristics of Drosophila flies, which continued to be one of the objects of their ob- servations. A second material for study has been the plant Tradescantia (spiderwort family), which offers a very favorable opportunity for cyto- plasmic study during microsporogenesis.6 Of particular interest has been the effort of this group to approach the problems of charting the submicro- scopic organization of chromosomes by means of "enzymatic dissection."

All these techniques were employed during the year, adding to the results obtained in other years. Experiments were conducted on the mutagenic properties of deoxyribonuclease when introduced into Drosophila. An enzyme analogue, 5-bromodeoxyuridine, was added to the list of mutagenic agents employed on both Drosophila and Tradescantia. Perhaps the most interesting results from this group's program during the year were two discoveries: (1) The finding that direct chromosomal breakage occurs in Tradescantia root tips in the presence of 5-bromodeoxyuridine. This enzyme analogue acts by modifying the base sequences in nucleic acid rather than the phosphate-sugar helices attacked by deoxyribonuclease. (2) The observation that Golgi bodies, one of the types of cytoplasmic organelle, exhibit different forms in the progression of microsporogenesis in Trades- cantia.

A third activity important to the 1961-1962 Department was not even dreamed of in 1905. It is represented in the work of Alfred D. Hershey and his associates, who are gradually charting the molecular structure of the viral chromosome. Dr. Hershey's work illustrates, more than anything else in the Department, the observation made by M. Demerec as early as 1942 that "From the purely biological science of early days, genetics has de- veloped into a science where cooperation with physics, chemistry, and mathematics is essential."7 Hershey and his associates observe in their

6 Microspore = pollen.

7 Year Book 41, p. 171.

34 CARNEGIE INSTITUTION OF WASHINGTON

report of this year that methods have been devised in recent years to characterize and differentiate among different types of deoxyribonucleic acid (DNA) molecules. Among these methods are optical analysis of thermal denaturation, chromatographic analysis, measurement of fragility and buoyant density, and specific enzymatic tests. But these tests do not give information about molecular structure, which remains a more or less "plausible inference." Hershey's objective is to remove genetics' dependence on inference for its concepts of molecular structure of genetic material. To this end, he and his associates are experimenting with the DNA of several types of bacteriophage.8 He considers these DNA's to be favorable material for experiment because: (1) they can be isolated in a molecularly homo- geneous state, permitting correlation between structure and biological function ; (2) their synthesis can be studied in infected cells that have been proved suitable for metabolic study in the past; and (3) present intensive study of the genetics of a few bacteriophage species gives valuable refer- ence points for physical and chemical findings. He considers his current work at least in part "exploratory."

Several interesting results ensued from Dr. Hershey's exploration of physical techniques in measuring molecular weight during the year. In one he established the molecular weight of the DNA of a bacteriophage known as T5 by first establishing an ingenious pair of "scales" by analyzing DNA fragments of another phage (T2). One scale is established by determining sedimentation constants9 of fragments of labeled T2 DNA as separated by column chromatography.10 The other was obtained from fragility tests that measured the rate of breakage of T2 DNA fragments of a given sedimenta- tion coefficient when stirred in a mixer at a given speed. The sedimentation coefficient9 and the fragility index of T5 DNA were then determined. By comparison with the T2 "scales" a molecular weight of 84 million was determined. The T5 DNA matched very closely fragments of T2 DNA in one sedimentation coefficient range (48.5-49.5).

By similar techniques Dr. Hershey also brought to light during the year some interesting molecular characteristics of the DNA of phage lambda, which was found to have astonishingly different molecular properties from other well known DNA's. Of particular interest was a broad range of denaturation temperatures, like that of bacterial DNA's and contrasting with an exceedingly narrow range typical of other phage DNA's. On one hand these and other properties suggest a marked tendency of the molecules to interact with each other, and on the other, a remarkable differentiation in structure along their lengths. These exceptional properties may be

8 Bacteriophage — any of a number of intracellular virus parasites of bacteria.

9 Measure of the rate of precipitation of particles in suspension in a solution when centrifuged.

10 Chromatography — a method of separating and analyzing chemical substances by inducing differential migration and adsorption from solution in a porous, insoluble, sorptive medium.

REPORT OF THE PRESIDENT 35

related to each other and to some of the well known biological peculiarities of phage lambda.

By infecting bacteria with isotopically labeled phage particles and by labeling DNA synthesized in the bacteria after infection, Dr. Hershey and Dr. F. R. Frankel have determined that cells subjected to such infection always contain a considerable fraction of their total DNA in a form indis- tinguishable from that found in finished phage particles. They note that this points to a mechanism for the preservation and determination of molecular length that operates continuously during DNA replication, not only at some terminal stage in the formation of the phage particle. This conclusion is considered significant evidence bearing upon several hypoth- eses about genetic mechanisms.

The Department of Plant Biology

The Department of Plant Biology also has developed from an operation under way in 1905. The Desert Botanical 1905 Laboratory was active that year, located at Tucson, Arizona. The program in 1905 was not as varied as that of the Station for Experimental Evolution. Twelve investigators were associated with the Laboratory in that year, most of them as recipients of grants. As might be expected, their investigations were heavily weighted toward the characteristics of arid-region plants, especially transpiration11 and water-conducting mechanisms. A substantial amount of attention was paid to the character of plant environment, as in D. T. MacDougal's observations of soil temperature and B. E. Livingston's study of the relations of desert plants to soil moisture and evaporation. More typical, however, was F. E. Lloyd's study of correlation between stomatal12 action and transpiration in certain types of desert plants. (No positive correlation was observed.) But along with these was displayed at least a secondary interest in what later became biochemistry and biophysics. For example, A. L. Dean conducted an " Investigation of the proteolytic enzymes of plants" and W. T. Swingle received a grant for an "Investigation of electro- magnetic and electrostatic effects on lines of force found in living plant cells." No conclusive results were reported from the latter study, but Dean reported finding an ereptic enzyme13 in all tissues of a species of bean (Phaseolus vulgaris).

11 Transpiration — the escape of water vapor from living plants.

12 Stomata — minute pores in the epidermis of plants, through which gases and water enter or escape from the plant.

13 A type of enzyme that breaks down proteoses and peptones, as in the intestinal tract of animals.

86 CARNEGIE INSTITUTION OF WASHINGTON

Most interesting about the program of the Desert Botanical Laboratory in 1905 was the complete absence of any attention to the problems of photo- synthesis, which have since become a major preoccupation of the Depart- ment of Plant Biology. Although the basic physical-chemical relations of photosynthesis14 had been suggested sixty years before, there was no hint of the importance of these problems in the 1905 program. Th. W. Engelmann in 1887 discovered that light absorbed by pigments other than chlorophyll also produced photosynthesis, more than fifteen years before the establish- ment of the Laboratory. Even during the year of the 1905 report, the English plant physiologist, F. F. Blackman, demonstrated that photo- synthesis includes at least one "dark" reaction not initiated by light.

The interest of the Institution in photosynthesis actually began six years later, in 1911, when H. A. Spoehr came to the Department of Botan- ical Research at Tucson, which succeeded the Desert Botanical Laboratory. Spoehr first came to the Institution to study the "chemical physiology" of plants but very soon became immersed in the problems of photosynthesis, an interest he maintained actively until his retirement in 1950. Just as intensively as in Spoehr's time the Department of Plant Biology today applies its research efforts to the great problem of unraveling the complex- ities of photosynthesis.

The work of the Department in 1961-1962 on photosynthesis still centers on a problem the general outlines of which 1961-1962 emerged in Engelmann's time : the exact function of the two sets of pigments, chlorophyll and the accessory pigments, both of which induce photosynthesis. It is now supposed that photosynthesis comprises at least two photochemical events, one driven by chlorophyll a, the other by the accessory pigments. Two discoveries made about 1955 provided some evidence for this hypothesis. One discovery was Blinks' chromatic transient effect, a momentary change in photo- synthetic rate observed when light absorbed by chlorophyll is changed to a color absorbed by accessory pigments. The other was Emerson's enhance- ment effect. In this effect photosynthesis resulting from wavelengths absorbed by chlorophyll a alone, when augmented by wavelengths absorbed through accessory pigments, is increased more than would be predicted from the simple sum of the effects from both radiations presented separately. A major effort is now being made in the world of research to define the

14 Joseph Priestley demonstrated the production of "good air" (oxygen) by plants in 1772; Jan Ingenhousz in 1778 showed that the effect noted by Priestley resulted from the influence of sunlight; Jean Senebier noted in 1782 that "bad air" (carbon dioxide) was a necessary input; Lavoisier determined the composition of carbon dioxide in 1784; Nicolas de Saussure showed precisely in 1804 that water, light, and carbon dioxide were inputs, and oxygen plus organic matter outputs; Julius Mayer, through his concepts of the conservation of energy, in 1845 sug- gested the place of sunlight and vegetative organisms in chemical action taking place on a global basis at the earth's surface.

REPORT OF THE PRESIDENT 37

nature of these two essential photochemical reactions and relate them to the chain of events in photosynthesis that results in oxygen evolution and carbon dioxide reduction. As throughout the long history of research in photosynthesis, ingenious theories currently exist to explain in detail most of the known effects. Generally considered, each investigator has his own favored concept of the process, and the different hypotheses are not entirely compatible with one another. Further experiments and more comprehensive concepts are still needed for an adequate understanding of photosynthesis.

At the Department of Plant Biology, C. Stacy French and his associates continued their efforts to provide experimental evidence on the exact functions of the different plant pigments.

A year ago they found in a red alga (Porphyridium cruentum) that chlorophyll a but not the accessory pigment, phycoerythrin, produces a chemically unidentified substance that rapidly consumes oxygen. Some of it is left over after a light exposure, as is demonstrated by the temporarily accelerated rate of oxygen uptake after an exposure to light absorbed by chlorophyll a. This material is also believed to be an intermediate in the process of photosynthesis.

This year the persistence of the chemically unidentified material previ- ously formed by illumination of chlorophyll a was measured by French and Jeanette Brown. This was done by observing the increased oxygen pro- duction of the algae upon exposure to individual flashes of light at the wavelength absorbed by phycoerythrin. The presence of the material enhances the oxygen evolution by a light flash that activates phycoerythrin. The half-life of the material measured in this way was found to be about 18 seconds under certain conditions. By contrast, preillumination by phycoerythrin-absorbed light did not enhance oxygen production when chlorophyll a was subsequently activated.

Another series of experiments, made this year, shows even more complex relations between the effects of different pigments of green leaves. The story began about eighty years ago, when Engelmann found traces of oxygen evolution from isolated chloroplasts. This effect was further investigated by Molish early in this century, but since then the reaction has had very little attention until recently, no doubt owing to R. Hill's discovery in 1937 that the addition of oxidants such as ferricyanide greatly increases the amount of oxygen produced. An avalanche of papers on the Hill reaction followed, and experiments with the evolution of oxygen from within chloroplasts without added substances have been all but abandoned.

In the past year, however, Y. de Kouchkovsky of the Centre National de la Recherche Scientifique, Gif-sur-Yvette, France, and David C. Fork of the Department of Plant Biology, have reexamined this effect with greatly improved methods. The work, started independently at the two laboratories,

38 CARNEGIE INSTITUTION OF WASHINGTON

was continued as a collaborative effort during Dr. Fork's visit to Gif-sur- Yvette in March 1962.

By measuring oxygen exchange of Swiss chard chloroplasts Fork showed that it is possible to distinguish four separate effects of light, each with its characteristic action spectrum. They are:

1. The evolution of oxygen from chloroplasts without added oxidants is driven most effectively by light having a wavelength of 650 millimicrons (red).15 This corresponds to the absorption peak of chlorophyll b in chloro- plasts, thereby showing that chlorophyll b is more effective than chlorophyll a in this reaction. A shoulder on the curve of the action spectrum, however, shows that at least one of the three forms of chlorophyll a is also active. This oxygen production within the chloroplast goes rapidly for only a few seconds, then its rate drops to a very low value. Storage in the dark revives the ability to evolve oxygen. Apparently light consumes some material found in chloroplasts which is restored in darkness.

2. Dr. Fork found the recovery process to be strongly accelerated by exposure to far-red light. A wavelength of about 730 millimicrons was most effective for this purpose. This wavelength suggests identity with phy to- chrome, a substance which, though present in very small amounts, controls many plant responses. In addition to the 730-millimicron peak, however, the action spectrum for the regeneration of the chloroplasts' ability to evolve oxygen also has a peak in the blue wavelengths which does not activate phytochrome.

3. Ferricyanide [K3Fe(CN)e], when added to chloroplasts, substitutes for the natural oxidant substance responsible for photoproduction of oxygen. The rate of oxygen evolution remains for long light exposures, and the action spectrum, which peaks at 678 millimicrons, shows that chlorophyll a is more effective than chlorophyll b when ferricyanide is present.

4. A very specific inhibitor for oxygen production by chloroplasts is the herbicide DCMU.16 When this poison is added to chloroplasts the photo- consumption of oxygen can be measured without interference by oxygen evolution and shows a maximum efficiency at wavelength 690 millimicrons (red).

Four different action spectra have thus been measured for oxygen exchange in isolated chloroplasts. French raises the question of the exact function of each pigment in these various photoprocesses. He says that the answer is clear for chlorophylls a and b (678- and 650-millimicron peaks) : they are concerned with oxygen evolution. But it is not yet known why chlorophyll b is more effective than chlorophyll a for the reaction within the

15 One millimicron = 10-6 millimeter.

16 3-(3,4-Dichlorophenyl)-l,l-dimethylurea; manufactured by E. I. du Pont de Nemours and Company.

REPORT OF THE PRESIDENT 39

natural chloroplast whereas the reverse is true when ferrieyanide is added.

The two action spectra with peaks at 730 and 690 millimicrons are more obscure. They do not necessarily indicate that there are active pigments with absorption maxima at either wavelength. Instead, spectra may result from the activation of two pigments whose reactions either reinforce or counteract each other. In both cases the action spectra maxima may differ greatly from the absorption maxima of the reacting pigments. These are interesting subjects for further investigation.

Ellen C. Weaver started an attack on the problems of photosynthesis with an intriguing and promising new technique, that of electron para- magnetic17 resonance (EPR) spectroscopy. She notes in her report the well established fact that illuminated chlorophyll-containing material has a higher level of unpaired electrons than material in the dark, suggesting that some phase of photosynthesis proceeds by single-electron transfers. Even though several research groups outside the Institution had employed this new technique (about six years old) in studying photosynthesis, no rigorous demonstration had yet been made that electron resonance18 had a direct connection with photosynthesis.

Dr. Weaver set out during the year first to determine whether or not the established resonance was associated with chlorophyll. She observed two distinctly different light-induced resonances. One is the R (rapid-decaying) signal, seen only when cells are illuminated. The other may persist for hours in the absence of light, and it is designated the S (slow-decaying) signal. Using a yellow mutant (no chlorophyll) of the fresh-water alga Chlamy- domonas reinhardi, Dr. Weaver obtained no R signals in EPR observation, suggesting that the R signal is ascribable to chlorophyll. She also discovered by using dilute cell suspensions that 680-millimicron light (near the absorp- tion peak for chlorophyll a) was the most effective for producing the R signals. Another interesting result is her discovery that the amplitude of the R signal has a strictly linear (proportional) relation to light intensity for the wavelengths least absorbed by chlorophyll, whereas wavelengths most strongly absorbed by chlorophyll have no linear relation to light intensity (assuming low light levels in both cases). Dr. Weaver's tentative conclusion from these observations is that the R signal is associated with chlorophyll and arises from the "primary" act of photosynthesis.

Dr. Weaver also discovered that any inhibition of oxygen evolution, as by DCMU or by limiting the manganese-ion concentration in the growing medium, will produce an enhanced R signal. This suggests that if the

17 Paramagnetic — atoms having spin systems with magnetic moment (or materials containing those atoms) are paramagnetic.

18 Electron resonance — a property of unpaired electrons, whereby precession of the spinning electron may be inferred when it is subjected to an electromagnetic field at a specific frequency, as in EPR spectroscopy.

40 CARNEGIE INSTITUTION OF WASHINGTON

pathway of the electrons is in any way obstructed the net level of unpaired spins rises. The result indicates further that the alteration of photosynthetic processes other than oxygen evolution may provide a fruitful field for experiment using the EPR spectroscopic technique. Interestingly, the S (slow-decaying) signal is not altered by blocking the oxygen evolution pathway with DCMU, but manganese starvation reduces that signal to an extremely low level. It is thought that this result may be correlated with a lack of plastoquinone,19 previously determined elsewhere to be a necessary and apparently universal factor in the oxygen evolution of green plants.

Dr. Weaver has thus presented evidence that chlorophyll is the source of one type of free electrons in an intact photosynthetic organism and that plastoquinone is the site of another type. She has also demonstrated the correlation of the two types of signals with the evolution of photosynthetic oxygen. The method and her results are of more than usual interest, because photosynthesis is essentially a photoreduction process when viewed in a highly general way, that is, the transfer of electrons from one substance to another.

Although photosynthesis still presents an awesome complexity to those investigating it, studies like those of French, Fork, Brown, and Weaver examining the effects of light on metabolic reactions are continually changing concepts of how synthesis takes place and, step by step, are build- ing a more complete understanding of this vastly important phenomenon.

Another field in plant biology, experimental taxonomy, can trace its origin to the activities of the 1905 Desert Laboratory. Again, however, the diffuse approach of 1905 is gone. William M. Hiesey and his associates note in the 1961-1962 report that current developments in precise techniques have greatly extended the horizon of this field. Instead of the compart- mentalizing of botanical study, which was commencing in 1905, they see "a truly integrated plant science whereby contributions from the various specialized fields, including taxonomy, ecology, cytology, genetics, physi- ology, developmental morphology, and biochemistry, can be incorporated in a panoramic view of plant relationships and evolution." Their goal is an integrated understanding of the chain of mechanisms that determine plant evolution, including the genetic and the biochemical. For a number of years plants of the genus Mimulus20 had been used for comparative growth studies of altitudinal effects at the Stanford, Mather, and Timberline stations. More recently the races of one species, Mimulus cardinalis, have been subjected to controlled growth chamber experiments.

During the year Harold W. Milner made some particularly interesting

19 Plastoquinone — quinone found in chloroplasts ; the structure of this compound is given in figure 31 of the report of the Department of Plant Biology.

20 The garden "monkey flower" belongs to the Mimulus genus.

REPORT OF THE PRESIDENT J^.1

studies of the photosynthetic rates of six races of the species originating in diverse climates and altitudes. Among the variations observed were a 60 per cent difference among the races in the light intensity required to saturate photosynthesis at high temperature, and a 100 per cent difference at a very low temperature (0°C). Significant variance in photosynthetic rate at extreme temperatures also was observed, as well as disparate abilities to maintain a high rate of photosynthesis over a long period. From these and other results one may conclude that climatic races within the same species may show differential patterns of response undoubtedly linked with vari- ations in internal physiology.

During the year an important step was taken toward establishing tissue cultures from Mimulus plants, so as to make quantitative measurements of growth and photosynthetic rates in tissue cultures similar to those for whole plants. By examining the physiological requirements of tissue from various plant organs, it should be possible to localize the site of physiological differences within the plant.

In addition, the group extended its work during the year to species of Solidago (goldenrod), particularly in the collaborative work of Malcolm Nobs of the Department working at the Institute of Plant Systematics and Genetics at Uppsala, Sweden. The same type of difference in response to light intensity was observed between two races of Solidago virgaurea: one a shade-loving race from Sweden and the other an alpine race from Norway. The alpine race has a much higher requirement for light saturation than the shade race, and its chloroplasts remain normal at light intensities that cause the disintegration of those from the shade race.

The Department of Terrestrial Magnetism

The Department of Terrestrial Magnetism was also among the active Departments of the Institution in the year 1905. 1905 The work of the Department in 1905 faithfully followed its name, although a wide range of projects was reported, with activity on an almost worldwide basis. A major preoccupa- tion of the Department during that year was an effort to start a systematic series of magnetic observations on most parts of the globe, which at that time were informational blanks. L. A. Bauer, Director of the Department in that year, stated, "our progress with regard to the great and principal facts of the earth's magnetism will be at a standstill unless a magnetic survey of the whole globe be undertaken immediately." Toward that end a wooden sailing vessel, the brig Galilee, had been manned and outfitted, and had undertaken trial runs. This was the beginning of a program that

42 CARNEGIE INSTITUTION OF WASHINGTON

continued for almost 25 years thereafter, in which the sailing vessels Galilee and Carnegie logged more than 400,000 miles to undertake magnetic and other scientific observations in every ocean area of the globe. It ended only with the accidental destruction by fire of the Carnegie at Samoa in Novem- ber 1929.

A very extensive land survey program also was being initiated for magnetic observations in 1905. Many of the islands of the West Indies were covered in that year, and arrangements were being completed for observa- tions on the South Pacific Islands and in Canada, Mexico, Central America, South America, and China. Cooperative arrangements for observations and research were maintained with several German scientific institutions and with the St. Petersburg Academy of Sciences in Russia.

Besides its primary program on the study of and basic data collection for terrestrial magnetism, the Department in 1905 organized and participated in the program of observing the solar eclipse of that year, and it began cooperating with the Institution's Solar Observatory in the study of several solar phenomena.

The Institution in 1905 also expressed a substantial interest in physics research, but entirely through a program of grants to fourteen American physicists. Among the grants were several for studies of emission spectra and a study of the theory of light.

Although the emphasis so prominent in the 1905 program of the Department of Terrestrial Magnetism was continued 1961-1962 until the early 1930's with relatively slight changes, the program of 1961-1962 in the Department was a much differ- ent one. The principal activities reminiscent of the earlier days of the Department came in the research of Scott E. Forbush, but again in an environment strikingly different from that of the first twenty-five years of the Department. Forbush's principal investigations during the report year were devoted to the intensity of the charged particles in the Van Allen trapped-radiation belt adjacent to the earth, as recorded during the transits of the satellite Explorer VII through the belt between 1959 and 1960. He also had under way studies examining the southward shift of the auroral-zone current system during magnetic storms in its probable associ- ation with particles coming from the outer Van Allen belt.

The bulk of the Department's varied and imaginative research in 1961- 1962, however, derived from applying the techniques of physics to a wide variety of geophysical and biological problems. They ranged from the ex- amination of the interior of living cells to charting the hydrogen clouds of our Galaxy.

Perhaps the most significant results to emerge from the year's work were from a quarter that could hardly have been envisioned as associated with

REPORT OF THE PRESIDENT /$

the Department even twenty years ago. They came from the work of the Biophysics Section (E. T. Bolton, R. J. Britten, D. B. Cowie, B. J. Mc- Carthy, J. E. Midgley, and R. B. Roberts) on the fine structure of, and biochemical processes taking place within, bacterial and other cells.

As the end of the report year approached, the Section was engrossed in some striking experiments involving "messenger" ribonucleic acid (RNA). This type of RNA contains nucleotide21 sequences complementary to those in the appropriate DNA which provides the genetic information. In follow- ing a lead provided by E. K. F. Bautz and B. D. Hall at the University of Illinois it was discovered that single-stranded DNA could be immobilized in agar and complementary RNA could be caused to hybridize with it through the formation of hydrogen bonds. By washing, the immobilized hybrid DNA-RNA combination was freed of other contaminating RNA. The hybridized RNA could then be reclaimed, in a state of high purity, by dissociation of the hydrogen bonds, and could be chemically analyzed.

With this simple and effective new procedure it has been possible to demonstrate that the DNA-like RNA comprises about 1 per cent of the total RNA of bacterial cells and that it has a half-life during active syn- thesis of approximately 2 minutes. On the assumption that this RNA is in fact the active template for protein synthesis, the measurements of its quantity and half-life show that a single molecule acts catalytically for the synthesis of many polypeptide22 chains.

Further work has revealed that the method can be used to exploit the specificity inherent in the hybridization process, which depends upon long regions of complementary nucleotide sequences in molecules of RNA and DNA. Thus, RNA from bacteriophage T2 will hybridize well with DNA of the genetically closely related phage T4 but not with the apparently unrelated T7 DNA. Several species of bacteria have also been tested, and cross reactions have been found to occur to a greater or lesser degree in accord with accepted taxonomic relationships. Thus, the method has made feasible a quantitative chemical analysis of the amount of genetic informa- tion held in common among species.

Since the method is a general one, applying to the DNA of all species and tissues, it can be used in studies of the transcription of genetic information and of differentiation, two of the key subjects of modern biology.

During the year the Biophysics Section also contributed a new hypothesis about the code associated with the role of nucleic acid in specifying the order of amino acids in protein. The prevailing hypothesis interprets ex- perimental findings in terms of a "three-letter" or triplet code. The experi-

21 Precursor of or decomposition product from nucleic acid, composed of a nitrogenous base, a ribose sugar, and phosphoric acid.

22 Peptides are proteins linked by amide (RCO-NHR/), or "peptide," bond.

44 CARNEGIE INSTITUTION OF WASHINGTON

ments of the Section lead its members to believe that a two-letter or doublet code eliminates the major failing of the triplet code, which implies an un- realistically high uridylic acid23 content for the "template" material of protein synthesis. The doublet code apparently provides a good correlation between the amino acid composition of the bacterially synthesized protein and the nucleotide composition of the RNA templates on which it is formed.

Other fields in which the techniques of physics are being applied by Staff Members of the Department are seismological exploration of the earth's crust, radioactive dating of rocks, radio astronomy, and the development of image tubes for use in astronomical studies.

It is of particular interest that all these programs in one respect or another are cooperative, carrying on the tradition of joint investigations or joint enterprise which was started and even widely used in the earliest days of the Department. As Merle Tuve, the Director of the Department, observes in the introduction of his 1961-1962 report, " 'cooperation' . . . has many very different aspects in the current work of the Department, but in each case it represents a situation where there is special usefulness in our freedom of initiative and recognition of the infectious characteristic of personal enthusiasm." To some extent, the same thing might have been said for the programs in biophysics and geomagnetic studies.

A good example of the Department's cooperative approach is shown in its radio astronomy program. With the support of the National Science Foundation a new Carnegie Radio Astronomy Station will soon be estab- lished in Argentina. Parts for a major instrument, a parabolic antenna nearly 100 feet (30 meters) in diameter, are now being manufactured in this country and will be shipped to Buenos Aires for assembly there during 1962-1963. The Argentinian National Council for Scientific and Technical Investigations and the Research Council of the State of Buenos Aires have created a new National Institute of Radio Astronomy to participate in the construction and operation of the station. Later operation will be a cooper- ative venture among the Carnegie Institution, the University of Buenos Aires, and the University of La Plata. Invitations will be extended to astronomers in other institutions in South America to participate in the research program. Some fellowships are being offered by the Institution to bring students and professional research men interested in radio astronomy to this country for training in the use of parabolic antennas and for ac- quiring educational background in radio astronomy.

The observational program in radio astronomy using the Department's

23 Uridylic acid — a nucleotide; technically uracil (2,6-dioxypyrimidine) + D-ribose sugar -f- phosphoric acid.

REPORT OF THE PRESIDENT £5

instruments also continued during the year. Observations of the hydrogen gas content at the center of our Galaxy confirmed previous observations at Leiden, the Netherlands, and Sydney, Australia, that the motions of hy- drogen close to the Galactic center are complex, and that the hydrogen gas not only is rotating about the center of the Galactic mass but also is ex- panding. Because of its latitudinal position, the Derwood, Maryland, Station of the Department was able to extend observations nearly 20° farther south along the Galactic plane than the Dutch station.

The Department also decided during the year, after considerable experi- ment, to begin construction of an interferometer array from parabolic dish antennas, to be able to obtain precise positions of radio noise sources in the sky. A 30-meter dish closely following the design of the Argentinian radio telescope is now being constructed at Derwood and will be used with the existing 60-foot parabolic antenna as a two-element interferometer. These two antennas will be employed in experiment to evaluate the po- tentialities of such a system in determining precise radio-star positions.

A second cooperative venture of the Department in the area of astro- nomical study has been the work of the Committee on Image Tubes for Telescopes, of which Merle Tuve is chairman. In this the Department has collaborated with the Mount Wilson and Palomar Observatories, the Lowell Observatory, the National Bureau of Standards, and the United States Naval Observatory to develop electronic image tubes for magnifying signals received on optical telescopes. This work has also been supported in large part by generous grants from the National Science Foundation.

During the year the Committee continued the testing of tubes manu- factured experimentally upon its order by the International Telephone and Telegraph Corporation Laboratories and by the Radio Corporation of America. The tests conducted were largely undertaken by W. K. Ford, Jr., of the Department. The tubes proved to have better operating character- istics than the Committee had hoped for only three years ago. Telescope observations were made at the Lowell Observatory with the tubes to ex- amine their reliability and effectiveness, and laboratory investigations were conducted to distinguish among the relative merits of the several tubes. On the basis of the spectrographic tests from telescope observations and the laboratory tests, the Committee believes that the two types of tubes recently examined (mica-window and cascaded) will have wide application in astronomy because of their advantages over conventional photography. Development will be continued, again with the support of the grant from the National Science Foundation.

A major project of the seismic studies group in the Earth's Crust Section of the Department (J. S. Steinhart, L. T. Aldrich, M. A. Tuve, and associ- ates) was an intensive study of the earth's crust in Maine, in which col-

46 CARNEGIE INSTITUTION OF WASHINGTON

leagues from the University of Wisconsin, Princeton University, Penn- sylvania State University, the University of Michigan, and the Woods Hole Oceanographic Institution participated, and the United States Coast Guard assisted in detonating explosions in the Gulf of Maine in July 1961.

The data obtained from the explosions have since been the subject of appraisal to determine the application of explosion seismology to designation of crustal structures. This is a very real geological problem, because the traditional conception of the earth's crust as one or more horizontal layers of constant seismic wave velocity has appeared inadequate for more than a decade. Efforts to find the proper reflections from the surfaces of the sup- posed layers have been unsuccessful; and laboratory measurements of seismic velocities in various rock types contradict the layer hypothesis. Field evidence suggests significant lateral as well as vertical differences in structure. Several models that might conform to the seismic results received from the explosions were therefore constructed.

On the basis of these models it seems fairly certain that in Maine the Mohorovicic discontinuity24 lies at 36 ± 3 kilometers below the surface. The most likely models suggest that the upper 3 kilometers of the crust is granitic and that below the granite the percentage of gabbro25 increases at a rate that maintains a steady gradient in seismic wave velocity change to a depth of about 20 kilometers. These findings are of interest geologically in that they postulate appreciably less granitic material than is customarily thought to be in a continental crust.

The radioactive dating group is not only interinstitutional but also interdepartmental (L. T. Aldrich and S. R. Hart of the Department of Terrestrial Magnetism, G. L. Davis, G. R. Tilton, and B. R. Doe of the Geophysical Laboratory and associates). During the year the Department of Terrestrial Magnetism members of the group participated in an exchange program with the Geological and Mineralogical Institute of the University of Kyoto.

Dr. I. Hayase, of the University of Kyoto, spent part of the year at the Department becoming familiar with its techniques of measuring mineral ages. In the course of his visit he analyzed samples collected in Japan. The data were of interest as the first measurement of the kind from Japan. They showed no contradictions between the isotopically determined ages and ages implied by geological structure. They also showed discordances between rubidium-strontium and potassium-argon age determinations commonly enough to indicate a complex geological history for the Islands.

As a second part of the exchange, L. T. Aldrich of the Department is now

24 A phenomenon recorded in the changing speed of seismic waves at certain depths.

25 A granitic rock formed of plagioclase (light-colored) feldspar and a monoclinic pyroxene like augite (dark-colored).

REPORT OF THE PRESIDENT Jfl

in Kyoto as a visiting professor at the University. He is assisting in the establishment of a complete laboratory for the measurement of mineral ages. To facilitate this work the Department constructed and shipped to the University a mass spectrometer26 which Dr. Aldrich now has in opera- tion at the Institute there. It is expected that the spectrometer will serve as a model for similar equipment to be built elsewhere in Japan. We hope that this particular interinstitutional collaboration will continue indefinitely.

The Geophysical Laboratory members of the group also worked with a staff member of the Geological Survey of Finland, O. Kouvo, on the dating in two orogenic (mountain-building) belts in Finland: the Karelian belt extending from southeastern Finland northwesterly to Finnish Lapland, and the Svecofennian extending east-west in southern Finland. It is gener- ally believed by geologists that the Svecofennian belt is older than the Karelian. The radioactive dating work, however, gives strong evidence that the intrusion of igneous rocks occurred about 1.9 billion years ago in both orogenic belts, and the two orogenies therefore are approximately con- temporary.

The radioactive dating group has also compiled a new map of age dis- tribution in crystalline basement rocks of North America. This shows one belt of rocks, ranging from 0.9 to 1.2 billion years old, extending from Labrador to Texas; another, 1.2 to 1.55 billion years old, occupying a large part of the central and southwestern part of the country; a third, 2.0 to 2.8 billion years of age, from the Rocky Mountains northeastward over the Laurentian Shield to Quebec; and still another, 1.55 to 2 billion years old, in Alberta and northwestern Canada. A picture of the geographical differ- entiation of ancient rocks in North America is thus beginning to emerge.

In cooperation with the University of Basel, Switzerland, the Department completed the installation of a polarized ion source in the departmental accelerator during the year. It consists of a discharge tube for the production of atomic hydrogen, diaphragms and pumps for defining the atomic beam, a quadrupole magnet for selecting and focusing the atoms having the de- sired orientation, an ionizer for the atomic beam, and a device for pre- accelerating and focusing the ionized atoms. The machine was operated successfully. It is planned to use the polarized deuteron beam in the study of a number of nuclear reactions, thus returning the Department more directly to the field of nuclear physics than at any time since the end of World War II. For more than fifteen years after the mid- 1 920 's the Department maintained a pioneering effort in nuclear physics, operating one of the first accelerators in this country.

26 Mass spectrometer — an instrument for determining the masses of atoms or molecules in a gas, liquid, or solid. In it a beam of ions is directed through electric and magnetic fields so as to produce a mass spectrum identifiable by an electrical detector.

48 CARNEGIE INSTITUTION OF WASHINGTON

The Geophysical Laboratory

Other than the Terrestrial Magnetism program, geophys- ical research in 1905 was not carried on within the premises 1905 of the Institution but nonetheless was considered an im- portant part of the total program. It was the type of project that President Woodward advocated continuing, in his " Suggestions Concerning Pending Problems of the Institution."27 Indeed, a large part of the total geophysical program in that year was carried on in close collaboration with the United States Geological Survey in Wash- ington, thus commencing a friendly professional relation that has continued ever since. The two principal investigators of that year, Arthur L. Day and G. F. Becker, held appointments in the Survey even though a substantial proportion of Dr. Day's time was spent on Institution projects. Included was a three-month visit by Dr. Day to Europe for the purpose of studying laboratory equipment for geophysical research and making an inventory of European research.

Becker's research was concerned entirely with an effort to determine experimentally the relation between stress and strain. The main part of his apparatus was a 3-inch tube 480 feet long erected in the Washington Monu- ment, within which steel tapes were suspended. He made some observations by means of this equipment during the year. In another project, F. D. Adams of McGill University conducted experiments on the cubic compressi- bility, the modulus of shear, and the flow of rocks, in which hundred-ton pressures were used.

The heart of the 1905 program, however, lay in the work of Dr. Day. Much of his time was spent in setting up his newly designed laboratory equipment. It comprised, among other apparatus, a furnace capable of reaching 2100°C in oxidizing or reducing atmospheres, a large electric furnace in which pressures up to 500 pounds or a vacuum could be main- tained, and a water-pressure plant capable of reaching 2000 atmospheres. A similar plant capable of reaching 3000 atmospheres was under construc- tion. Dr. Day's research included the completion of a three-year investi- gation of the lime-soda feldspar28 group of rocks. His results showed "that the lime-soda feldspars form a continuous series of mixed crystals capable of stable existence in any proportion of the two component minerals. " Experimental proof of this isomorphism was established by correlating melting points with change in the mixes of the two components. Experi- ments also were conducted on wollastonite (CaSi03), determining for the first time the exact temperature of crystallization of this mineral as found in nature.

27 Year Book 4, pp. 28-29.

28 Feldspar is one component of granite.

REPORT OF THE PRESIDENT 1^9

Inspired by his thought on silicates, Dr. Day already was looking toward the future, as he mentioned two practical problems to which his laboratory later contributed most significantly. He notes that "the study of lime-silica mixtures is fundamental in the preparation of Portland cement. Questions of technical interest in glass manufacture reappear everywhere in handling silicate solutions."29 He concluded in a satisfied vein, "grave doubts were entertained as to the feasibility of handling physical phenomena at high temperatures with anything like the certainty attained at ordinary tem- peratures, but the experience of this first year has justified the effort ... ." If Dr. Day could look in on the Geophysical Laboratory of today he should feel greatly gratified, both because his 1961-1962 beginning work in 1905 accurately forecast a direction and method of research that continues to be highly productive after nearly sixty years and because of the enormously great range and resolving power of the methods now in use.

The techniques upon which the Laboratory depend have become enor- mously more powerful and more sensitive than in Dr. Day's time. The 3000-atmosphere pressures, which were tremendous to Dr. Day, have been succeeded in 1961-1962 by pressures of 100,000 atmospheres. Moreover, these elevated pressures can be employed in combination with almost any temperature needed in geophysical experiment. In Dr. Day's 1905 experi- ments, high temperatures could be accompanied by a pressure of only a few hundred pounds. The present-day Laboratory has firm grasp of these tools, and it applies them to the whole range of problems on the frontiers of modern geology. From the first explorations of the potentiality of these geophysical techniques it has arrived at the full power of applying them to revelation of the earth's interior and its history. Furthermore, the capacities of the Laboratory now include a wide variety of techniques — beyond those of high temperature and high pressure — taken from modern physics, chemistry, and mathematics. The Department of 1961-1962 included work in experimental petrology, statistical petrology, crystallography, ore minerals, meteorite analysis, geothermal calculations, the ages of rocks and minerals, and organic geochemistry.

Among the numerous investigations carried on in these fields in 1961- 1962, three will be described briefly to illustrate more in detail the charac- teristics of research at the Geophysical Laboratory. These are experimental petrology, in which much of the work this year was focused on pyroxene minerals, and emphasized the study of phase equilibria30 at higher pressures;

29 Later work of the Laboratory made fundamental contributions to the technology of both industries.

30 In chemical terms, any crystalline compound or liquid is a phase ; hence, a mineral separated from a rock is also a phase. Assemblages of phases (or minerals) which do not melt or react at a particular temperature and pressure are said to be at equilibrium. Study of these mineral equi- libria is a means of understanding the conditions of formation of rocks.

50 CARNEGIE INSTITUTION OF WASHINGTON

the mineralogy of meteorites; and organic geochemistry, including analysis of Precambrian carbonaceous materials.

The program of studying the mineralogical composition of meteorites, begun last year, continued to produce most interesting results. Particularly relevant as a preview of the solid matter to be found in the spatial environs of the earth, the meteorites studied are continuing to yield mineralogical surprises. P. Ramdohr and G. Kullerud examined more than a hundred stony meteorites during the year, rinding in them fourteen new minerals thought to be observed for the first time anywhere. Only one of them has been given a name, the others being referred to simply by letters of the alphabet for the time being. Because they occur in amounts too small to permit performance of standard chemical analyses or X-ray powder diffraction studies, the component elements in only two have been identified. These were a nickel-iron sulfide [(NiFe)2S] called the Henderson phase, and a colorless mineral of spinel31 type (Mg2Ti04). Several of the remaining twelve minerals are thought to be sulfides, and one, having an hexagonal layered structure, seems to be a compound of iron, carbon, and sulfur. One is thought to contain arsenic. The electron probe is considered to have promising potentialities for assisting in the chemical identification of these minerals. Another method of identification of the new phases is synthesis, once the major constituents are surmised from deductions about the origin of the minerals. Ramdohr and Kullerud state that their efforts in this direction are increasingly successful.

Ramdohr and Kullerud also made a number of observations on distinctive structural and textural phenomena in meteorites. They include evidences of mechanical distortion and crystallization in many meteorites, evidence of spontaneous melting in the interior of many, and the effects of terrestrial weathering, which may yield products that may be mistaken for primary components. Magnetite (Fe304) frequently may be such a product. In another set of analyses on meteorites, S. P. Clark, Jr., has identified an unknown mineral in tektites (glassy bodies probably of meteoric origin) as schreibersite (Fe3P). He concludes that the content of minor elements in meteoric bodies, like sulfur, phosphorus, or carbon, should be helpful in identifying the number of meteoric falls in complex fields like those of southeast Asia or Australia. Presumably the minor elements would be the same in each fall but would differ in separate falls.

Another development of 1961-1962 meriting special mention is the study of phase equilibria at high pressures. This study has extended over sev-

31 Spinel is typically magnesium aluminate (MgO-Al203), but it has a wide variety of forms containing ferrous iron, manganese, ferric iron, and chromium. It may be red, yellow, green, black, or some other color. A general formula is R"0 -R/'^Os, where R" may be one of the bivalent metals, magnesium, zinc, manganese, iron, nickel, cobalt, or cadmium, and R"' may be trivalent aluminum, cobalt, iron, chromium, or gallium.

REPORT OF THE PRESIDENT 51

eral years and has drawn increasing effort by Laboratory Staff Members.

Geochemical studies at pressures up to 100,000 atmospheres have per- mitted geologists to take a fresh approach to various problems that have been the subject of spirited theoretical discussion for decades. Is the Mohorovicic discontinuity a phase change from basalt to eclogite?32 Is it the same under the continents as under the oceans? What is the mineralogy of the earth's mantle?33 Can the various types of basaltic lava be related to variations in the melting of mantle rocks at different depths and pressures? What temperatures are present in the lower mantle and core?34 As yet none of the questions can be fully answered, but the high-pressure studies of the last five years have contributed to an understanding of all and promise to contribute far more.

The Mohorovicic discontinuity continues to be one of the more absorbing geological problems. High-pressure high-temperature experiment with the synthesis of rocks expected at the depths of the discontinuity has given some indication of the rocks to be found there. Under the continents they are principally basalt and eclogite. Basalt is transformed by high pressure to the denser eclogite. Eclogite consists essentially of jadeite-bearing pyroxene and pyrope-bearing garnet.35 Both jadeite [NaAl(Si03)2] and pyrope (Mg3Al2Si30i2) are high-pressure phases, and their pressure- temperature fields of stability have been established in recent years at elevated temperatures. Significantly, both the reactions leading to the formation of jadeite and pyrope take place in a relatively narrow pressure- temperature range. The experimental results now indicate that in the depth range 50 to 100 kilometers in the mantle, where basaltic lava is believed to form, the mineral assemblage will be characteristic of eclogites. The experi- mental data for the transition fit reasonably well the hypothesis that the continental Mohorovicic discontinuity is a basalt-eclogite transition. The nature of the discontinuity under the oceans apparently is different from the continental, and is a challenging question for future thought and experiment.

Additional experimental data for constructing concepts of the earth's mantle and crust are being obtained in quantity at the Laboratory from an examination of the melting relations of silicates at high pressure. As a result the present-day conceptions of reactions by which basalts form in the partial fusion of mantle rocks are wholly different from those of earlier workers. The system of petrology developed by N. L. Bowen and others

32 A dense rock equivalent in composition to basalt, found in association with Russian and South African diamond pipes, and occurring in rocks, elsewhere on the earth's surface, thought to originate from deep in the earth's mantle.

33 That part of the earth's interior between the Mohorovicic discontinuity and the core.

34 The core is thought to commence at a depth of about 2900 kilometers.

35 Garnet has the general formula R"R'"(Si04)3, where R" may be bivalent iron, magnesium, manganese, or calcium, and R'" may be trivalent iron, aluminum, or chromium.

52 CARNEGIE INSTITUTION OF WASHINGTON

earlier at this Laboratory from experiments at atmospheric pressure successfully explained many characteristics of igneous rocks. It now is clear, however, that pressures as low as 10,000 to 20,000 atmospheres produce very pronounced changes in crystal-liquid equilibria in silicate rock systems. Even though the data on phase relations at high pressures still do not permit the construction of a system of petrology for the lower crust and upper mantle of the earth, answers to some important questions are being obtained.

One of the intriguing questions concerned the formation of silica-saturated basalt rocks of the crust from silica-undersaturated mantle rocks. F. R. Boyd, Jr., and J. L. England experimented during the year with the melting of pyrope garnet, thought to be an important constituent of the mantle, at pressures prevailing where basalts are considered to be formed. They found that pyrope garnet melts incongruently at these pressures to spinel and liquid. This melting relationship could explain the formation of the silica- saturated basalts, such as are found in Hawaii, from the typical minerals assumed to be in the upper mantle.

Continuing the experiments reported in Year Book 60, H. S. Yoder, Jr., and C. E. Tilley examined the possible origin of alkali basalt and tholeiitic basalt, two groups of rocks that are very important components of the earth's crust. Their previous experiments with natural rocks and synthetic mineral systems established that the same magma (liquid rock), depending on pressure, could yield both types of basalt. They now have suggested mechanisms whereby both alkali and tholeiitic basalt may be generated from an eclogitic liquid deep within the earth's mantle.

Sydney P. Clark, Jr., J. F. Schairer, and John de Neufville have attacked the same problem with a different approach. They also believe that it is necessary to examine critically important systems of minerals in their entirety under pressure before inferences about melting and solidification within the mantle can be drawn with confidence. They chose to examine the important but complicated quaternary system36 that includes among its phases the oxides spinel and corundum, forsterite (Mg2Si04), diopside (CaMgSi206), pyrope garnet, various forms of silica, and still other minerals. Their experiments were conducted at atmospheric pressure and at a pressure of 20,000 atmospheres. Their observations showed a range of solid solution in pyroxene minerals (e.g., diopside and others) at high pressures that is far more extensive than in the same system at atmospheric pressure. Pressure therefore undoubtedly produces profound changes in the melting relations within at least this mineral system. For some of the compositions, the system at 20,000 atmospheres is not even qualitatively similar to the

36 Quaternary system — a system of phase relations among minerals having four end members, schematically expressible in a tetrahedral diagram.

REPORT OF THE PRESIDENT 53

system at atmospheric pressure, as in the appearance of quartz on the liquidus above 1000°C. The experiments showed that this system is well suited to the study of the complex chemical equilibria at high pressures. Further study should yield important contributions to the petrology of the earth's rocks at depth.

Heat is the source of energy for most geological processes, and knowledge of the temperatures at the depth of the core-mantle boundary37 in the earth is of fundamental importance. It is probable that the temperature at this depth is not far below the minimum melting temperature of rocks in the lower mantle and not far above the solidifying temperature of the iron- nickel alloy believed to comprise the outer core. Data obtained at low pres- sures showed that the slopes of silicate melting curves were two to five times greater than the slopes of the melting curves of most metals. However, recent results for diopside and a few other silicates at pressures up to 50,000 atmospheres yield diagrams with slopes having a pronounced curvature. Extrapolation of the diopside data to a pressure at the core-mantle bound- ary38 indicates that a temperature of 3750°C would be required to melt diopside there. Similar extrapolation of data on the melting of iron indicates a temperature of 5200° at the boundary. Although the uncertainties in these extrapolations are very numerous, it is interesting that the estimates are close. They are furthermore in rough agreement with estimates made by other, equally uncertain, methods.

An elegant example of the application of the sensitive and powerful modern research techniques in geophysics to a problem that scarcely could have been touched even a decade ago is shown in the identification of com- pounds characteristic of life from ancient rocks. P. H. Abelson and P. L. Parker have isolated fatty acids from rocks as old as 500,000,000 years. This is the oldest known occurrence of these substances. Among the compounds identified were the saturated acids myristic [CH3(CH)i2C02H], palmitic [CH3(CH)14C02H], and stearic [CH3(CH)16C02H], the last being the most abundant. Although the quantities found are minute (10 micrograms39 per gram of organic carbon), gas-liquid chromatography permits isolation, identification, and quantitative measurement of the individual acids, even when major amounts of impurities are present.

The same fatty acids were isolated from recent sediments. Palmitic acid was the major component in the young rocks, being as much as ten times as abundant as stearic acid, the more abundant in the old rocks. Thus although the fatty acids in very young and in old rocks are qualitatively similar a puzzling quantitative difference has been noted.

37 Postulated to be at a depth of about 2900 kilometers.

38 1,400,000 atmospheres.

39 A microgram is 0.000001 gram.

54 CARNEGIE INSTITUTION OF WASHINGTON

T. C. Hoering has investigated two important aspects of the geochemical record of very early life on earth. He has studied some of the earth's oldest sedimentary rocks, which contain structures geologists consider related to algal activity. He has measured stable carbon isotope ratios, C13/C12, in coexisting carbonates and reduced carbon obtained from these specimens. He has found that the isotopes have been fractionated into a C13-enriched carbonate phase and a C13-depleted reduced carbon phase. The amount of this fractionation is nearly identical to that found in contemporaneous algal cells and their associated carbonates. The magnitude of the effect is also similar to that found between limestones and coals of all geological ages. Such isotope fractionation is caused by a slightly different rate of photo- synthesis for molecules of carbon dioxide containing C12 as compared with those containing C13.

The samples examined include a limestone from the Belt Series of Glacier Park, Montana, with a minimum age of 1.2 billion years, the Randville dolomite of Crystal Falls, Michigan, with a minimum age of 1.5 billion years, and the Bulawayan limestone of Southern Rhodesia with a minimum age of 2.7 billion years. In these rocks, which are among the oldest known sedimentary rocks, the isotopic evidence is consistent with the presence of photosynthetic algae in the very early Precambrian era.

The second study by Hoering was on the reduced carbon of Precambrian sedimentary rocks. A successful effort was made to extract and partially identify organic molecules from them. By means of a number of chemical degradations he was able to liberate soluble fractions from the insoluble "fabric" of the reduced carbon. The fractions were analyzed with the aid of ultraviolet spectroscopy and chromatography. The results indicate that the insoluble reduced carbon may be related to the kerogen of more recent rocks. Kerogen is produced by interactions of organic products of cells when deposited in sediments deprived of oxygen. Thus additional evidence has been produced pointing to the existence of life in very early Precambrian times, more than two billion years ago.

Mount Wilson and Palomar Observatories

In 1905 the astronomical activities of the Institution were

mainly those of the Solar Observatory, whose building and

1905 equipment were under construction during the year, with

view to completion in 1906. Mount Wilson was considered an

especially favorable site because "The unusually favorable

atmospheric conditions which prevail day and night at the site of the

observatory have attracted the attention of astronomers and astrophysi-

REPORT OF THE PRESIDENT 55

cists generally. "40 "It has been been found that the average night-seeing is exceedingly good, while the low wind-velocity, coupled with the trans- parency of the atmosphere, afford. . . advantages which should render Mount Wilson an ideal site for the 5-foot reflector." George E. Hale, the Director, defined his purposes as: "(1) The investigation of the sun (a) as a typical star, in connection with the study of stellar evolution: (b) as the central body of the solar system, with special reference to possible changes in the intensity of its heat radiation, such as might influence the conditions of life upon the earth. (2) The choice of an effective mode of attack, involving (a) the application of new methods in solar research; (6) the investigation of stellar and nebular phenomena, especially such as are not within the reach of existing instruments ; and (c) the interpretation of these celestial phenomena by means of laboratory experiments." He was at this time already con- sidering the design of "a large reflecting telescope and of new types of instruments." He also looked forward to "The furtherance of international cooperation in astrophysical research through the invitation to Mount Wilson, from time to time, of investigators especially qualified to take advantage of the opportunities afforded. . . ."

A large part of Dr. Hale's report in 1905 was necessarily devoted to a statement on the numerous construction projects that had absorbed his attention during the year. They included ten buildings on Mount Wilson, and the Pasadena office and shop, which were constructed on land given by citizens of Pasadena. Dr. Hale nonetheless found time not only for instru- ment testing but also for an observing program and planning a future research program. Daily direct photographs of the sun on a scale of 6.7 inches to the solar diameter were taken on the Snow telescope. Observations were made to test an hypothesis of Dr. Hale's about the relation of calcium vapor to the faculae and plages41 of the sun. Some experimental study of the spectra of sunspots, plages, and the chromosphere was undertaken for instrument design. Photographs were also taken of bright stars with a long- focus grating spectrograph. They included a photograph of the blue region of the first-order spectrum of Arcturus, which required an exposure of 14 hours on three successive nights.

Visiting investigators had already found their way to Mount Wilson. E. E. Barnard of the Yerkes Observatory photographed the southern part of the Milky Way, described by Dr. Hale as "a most important contribution to our knowledge of the structure of the Milky Way and of the remarkable nebulae within it." The Smithsonian Institution also sent an expedition

40 Year Book 4, p. 25.

41 Faculae — small irregular bright patches in the photosphere (visible disk) of the sun, sur- rounding sunspots.

Plages — faculae of the chromosphere, which is the outer layer of the sun's "atmosphere," extending to a height of several thousand kilometers from the visible disk.

56 CARNEGIE INSTITUTION OF WASHINGTON

to the mountain for observing solar radiation, directed by C. G. Abbot. Other astronomical work supported by the Institution in 1905 included the compilation, by Lewis Boss of the Dudley Observatory, Albany, New York, of a Preliminary General Catalogue of Stars for the 6000 stars visible to the naked eye. Also included were grants to Simon Newcomb of Washing- ton, D. C., for an " Investigation of the mean motion of the moon," and a rather enigmatical grant "To aid investigations in mathematical astronomy, statistical methods, and economic science." The economic science part was never reported upon, either in 1905 or in the four succeeding years when Dr. Newcomb held sequel grants.

The program of 1961-1962 at the Observatory, as for each of

the four preceding Departments, differed vastly from its

1961-1962 ancestor of sixty years ago. The primary emphasis on solar

studies gave way in 1918 to a more general astronomy

program with the completion of the 100-inch telescope.

Nonetheless, solar observation and solar study have continued to the present

day, but with gradually decreasing emphasis. A major change came in 1958-

1959, with a decision to drastically curtail routine observations. Since then

solar studies have centered on the sun's magnetic fields, of which daily

observations are made with the aid of the solar magnetograph originated

and developed by H. D. and H. W. Babcock of the Observatories. Daily

solar magnetograms have been made since 1957.

During the 1961-1962 year R. F. Howard commenced an extensive study of the accumulated magnetograms to classify magnetic regions, and cor- related them with optical and radio phenomena. He has already obtained the very interesting finding that the unipolar magnetic (UM) regions of the sun correlate in their position with calcium absorption phenomena observed spectroscopically. It may thus now become possible to extend observation of UM regions backward for 50 years or more, using the Observatory's extensive collection of spectroheliograms showing the absorption lines of the elements.

Responding somewhat to the explosion of national interest in inter- planetary space, the year was also marked at the Observatories by renewed attention to the planets, which have been subject to recurring study at the Observatories in the past. It has seemed important to press ground-based observations like those that can be undertaken at the Observatories to the limits made possible with new photometric and infrared techniques, be- cause information about the planets can be acquired by these techniques at a cost of much less effort and money than by observations from rockets. G. Munch, with the collaboration of H. Spinrad of the Jet Propulsion Labora- tory of the California Institute of Technology, and R. Younkin of the same laboratory, began studies of the spectra of the major planets. Two

REPORT OF THE PRESIDENT 57

lines of the hydrogen molecule were found in the spectrum of Saturn, pro- viding the first firm evidence of the presence of hydrogen in the atmosphere of that planet. Spinrad also analyzed high-dispersion spectra of Venus, finding evidence of large changes in the temperature of the atmosphere of Venus. B. Murray of the California Institute of Technology continued studies of the photoelectric colorimetry of the moon with the Mount Wilson facilities.

A major part of the Observatories' program, however, has been devoted to a study of the masses, luminosities, surface temperatures, and chemical composition of stars, and the variation of luminosity and surface tempera- ture with age. During recent decades these have been among the major problems in astronomy. Even though such research has become increasingly important with time, steps toward the modern understanding of these phenomena date back to the early years of this century. The first important step was taken by E. Hertzsprung and H. N. Russell, when they plotted a diagram of the absolute magnitude of stars in the solar neighborhood against their surface temperatures as indicated by spectral class or color. They found that most stars fall in a narrow diagonal band on their diagram, the very hot giants being at one end and the cool dwarfs at the other. Later theoretical investigations based on nuclear physics showed that the fusion of hydrogen into helium was an important source of energy for most stars42 and that stars obtaining their energy from this reaction logically fall on the color-magnitude diagram in the narrow "main sequence" band noted by Hertzsprung and Russell.

During the second world war, Walter Baade of the Observatories made a detailed investigation of the stellar content of the Andromeda galaxy. He found that the brightest stars in its spiral arms are very hot giants similar to those in the solar neighborhood, which also is on a spiral arm. In the nucleus, however, the brightest stars were cool red giants. To differentiate these, Baade introduced the concept of Population I (younger) stars typically on the spiral arms and Population II (older) stars typically at galactic centers.

Theory then predicted that, as the hydrogen fuel approaches exhaustion in a stellar core, a star expands greatly but cools and thereby moves off the narrow main-sequence band in the color-magnitude diagram and becomes a red giant. Since the brightest stars use their fuel most rapidly this change starts at the upper end of the main sequence and moves down the sequence with time. Obviously, the hot giants in the solar neighborhood and in galactic spiral arms indicate a population of stars that have formed re- cently, whereas the red giants in a galactic nucleus represent a population of old stars. Theory permits one to go even further and fix the age of a group

42 The hydrogen-helium reaction is now considered ancillary to the hydrogen-deuterium-helium reaction.

58 CARNEGIE INSTITUTION OF WASHINGTON

of stars by observing the magnitude at which stars are just beginning to move off the main sequence. Color-magnitude diagrams have been con- structed for a large number of globular and galactic clusters43 by A. R. Sandage, H. C. Arp, and W. A. Baum of the Observatories, and many others. Ages of a few million up to ten billion or more years have been found.

With the aid of high-dispersion spectra it has become possible recently to make detailed quantitative chemical analyses of stellar atmospheres. The first studies of the sun and of bright nearby stars indicated a surprising uni- formity of chemical composition. When these measurements were extended to some of the distant older clusters, however, it was found that their stars were deficient in the heavier metallic elements, often by factors of 100 or more compared with the stars near the sun. Since most of the strong metallic lines fall in the ultraviolet ( U) region of the spectrum, a star of high metallic content exhibits a depressed U region compared with the blue (B) or green-yellow (V, " visible' ') spectral regions. Within the past two years astronomers at the Observatories have found it possible to fix the metallic content from a comparison of the magnitudes of a star measured in the U, B, and V regions. This makes feasible the extension of abundance determinations to stars far too faint for detailed spectrum analysis.

In general, old stars such as those in the globular clusters, or high- velocity stars,44 which presumably were formed at the same time as those in the galactic nucleus, are metal deficient compared with the younger stars. Theory suggests that metals are formed late in the evolution of a star, after the hydrogen fuel has been exhausted in the stellar core and the central temperature has increased to many times that of stars on the main sequence. Therefore the metal-containing material in recently formed stars has gone through one or more earlier generations of stars in which the metals are formed and then blown off into space either in a gradual flow45 or explosively in a nova or supernova outburst.

Obviously, a project to understand stars will require decades for comple- tion as well as investigation by many astronomers at a number of observa- tories. The Institution can take pride not only in the participation of the Observatories in the grand conception of such a project but also in their preeminent position as contributor of observational data leading to widen- ing views of the universe which these studies are providing. During the year 1961-1962 the staff of the Observatories skillfully exploited the wonderful instruments at their disposal to give us further insights on this frontier of

43 A globular cluster is a group of many thousands of stars arranged in a regular form showing spherical symmetry. Many are located outside the plane of the Milky Way. A smaller group of stars always found near the plane of the Milky Way is known as a galactic cluster.

44 A high-velocity star is a star that is moving about the galactic nucleus with a velocity markedly different from that of the sun.

45 As studied by A. Deutsch of the Observatories. See Year Book 59, p. 8, and other year books.

REPORT OF THE PRESIDENT

59

logT 4.5

M

bol -6

-4 -2

0 +2 +4 +6 +8 ♦10 ♦12

o

O o ° SUPERGIANTS

G ft NTS

UBGIANTS

BLUE STARS

WHITE STARS

YELLOW STARS

RED STARS

-8

(BRIGHTEST)

-6

-4 -2

0

+2

+4

+6

+8

+10

+12

(FAINTEST)

Generalized Hertzsprung-Russell diagram of star color-magnitude relation. Log T — logarithm of temperature, degrees Kelvin; Mboi = bolometric magnitude, as measured from calculated total energy emission. (Adapted from Cecilia Payne-Gaposchkin, Introduction to Astronomy, Prentice- Hall, New York, 1954.)

60 CARNEGIE INSTITUTION OF WASHINGTON

the universe. Among the results were new knowledge about the differences in chemical composition among stars, the correlation of chemical composi- tion and star movement, a determination of the time of formation of the Galaxy in which we are located, and new evidence on the expansion of the cosmos.

The staff of the Observatories participated in detailed chemical investiga- tions of a number of stars. J. Greenstein and R. A. Parker of the Observa- tories have collaborated with G. Wallerstein of the University of California, H. L. Heifer of the University of Rochester, and L. Aller of the University of Michigan to study one group of three red giant stars. They found that the common metals were only 1/500 as abundant in this group as in the sun, and the heavy elements strontium, zirconium, barium, cerium, and europium were deficient by a factor of 25,000. Considering the deficiencies, they estimate that these stars, which are part of our Galaxy, probably condensed within a few hundred million years after the formation of the Galaxy. In investigating several dozen peculiar B and A stars,46 J. Jugaku, W. L. W. Sargent, and L. T. Searle found that the abundances of individual elements vary erratically compared with neighboring elements in the periodic table, often fluctuating by factors of 100 or more. Elements found to have marked over- or underabundance in certain stars are beryllium, carbon, nitrogen, oxygen, silicon, phosphorus, and mercury.

For some years a group of stars have been recognized and designated as subdwarfs because they lie appreciably below the main sequence on the color-magnitude diagram. Early studies showed that they were metal- deficient, therefore old, stars. They have high velocities considered in relation to the sun. To learn more about these rather rare stars, A. Sandage and C. T. Kowal have started a program for the photoelectric observation of the ultraviolet-blue-visible magnitudes of the high-velocity stars given in the Giclas Proper Motion Catalogue. More than 100 new metal-deficient subdwarfs have been discovered among the 700 stars observed thus far. Spectroscopic studies by Greenstein and by Sandage of an enlarged sample of these subdwarfs confirmed the high velocity of all.

In a further effort to obtain information on the relation of the subdwarfs to other principal groups of stars, O. J. Eggen and Sandage studied the effect of "line blanketing"47 on the position of a star in the color-magnitude dia- gram. The results were of special astronomical interest, for Eggen and Sandage found that if proper correction is made for line blanketing the sub- dwarf stars move into the same position as normal dwarf stars on the main

46 The accepted spectral classification of stars designates them by arbitrary letters as O, B, A, F, G, K, and M. O and B stars have the highest temperatures, and M the lowest.

47 Line blanketing refers to the situation in which the abundance in a star of the metallic elements having strong absorption bands in the ultraviolet is so great that it causes an appreciable deficiency in the spectral region compared with other parts of the spectrum of the star.

REPORT OF THE PRESIDENT 61

sequence of the color-magnitude diagram. Thus another addition was made to our understanding of the wonderful order which astronomers have been slowly illuminating with the aid of modern instruments.

Eggen, D. Lynden-Bell, and Sandage also studied the orbits around the nucleus of our Galaxy of a large number of dwarf stars, including both the normal and subdwarf types. They find a close correlation between metal deficiency and the eccentricity and angular momentum of the stellar orbit. They interpret this as indicating that metal-deficient stars were formed in an early period while our Galaxy was rapidly contracting. From the age of these stars they were able to fix the time of formation of our Galaxy out of the medium of the universe at about ten billion years ago.

Studies of stellar properties are important not only for understanding the characteristics of the stars themselves but also to provide a firm basis for the measurements on which the conceptions of the structure and origin of the entire universe depend. For example, nearly all determinations of large astronomical distances depend on the comparison of the apparent brightness of a nearby object with that of an identical object in a distant cluster or galaxy. Thus cepheid variables48 were used by E. P. Hubble to fix the dis- tance of the nearby Andromeda galaxy, and the galaxies themselves were used to estimate the distances of clusters of galaxies at the extreme range of telescopic penetration into space. However, the discovery of different stellar populations with major differences in age and chemical composition raised many doubts about the identity in absolute magnitude of a star in our own neighborhood with that of a star in a nearby galaxy, which might or might not have similar age or chemical composition.

One of the uncertainties in these extrapolations toward a picture of the universe has been the effect of light absorption by dust clouds along the path between star and observer. This is especially troublesome, since the shorter wavelengths of the spectrum are absorbed more strongly than the longer, producing a reddening effect. During the year H. C. Arp reexamined this problem in color-magnitude studies of globular clusters of stars. He found that the correction for absorption should be appreciably larger than had been allowed formerly. A substantial revision downward of previously determined globular cluster ages therefore must be made. This also elimi- nates a discrepancy existing between age determined from position on the color-magnitude diagram and age determined from models of cosmological expansion. They now become consistent.

Extrapolations to distant galaxies are also handicapped because most are too distant to permit observation of enough stars for the construction of a color-magnitude diagram. However, it is possible to analyze the integrated

48 Stars whose light emission varies in a definite pattern over a relatively short period but longer than 24 hours.

62 CARNEGIE INSTITUTION OF WASHINGTON

light received from a galaxy and from it obtain information about the distribution in temperature, magnitude, and chemical composition of the component stars. W. A. Baum has studied some nearby galaxies of different types by photoelectric scanning methods in order to obtain information about the evolution of galaxies. His evidence indicates that some definitely are composed of true Population II (older) stars whereas others (large ellipticals) have mainly Population I stars. Such observations are important in the construction and interpretation of cosmological models. Present interpretation of the observable universe conceives it as having a radius of five billion or so light years,49 expanding at its limits of observation at nearly half the speed of light. This interpretation depends on assumptions made about the magnitude-redshift relation, that is the reddening of the observed spectrum caused by recession of the distant galaxies in relation to the solar system. Distant galaxies, of course, are seen at an earlier age than nearby ones — billions of years of difference for the most distant. Since individual stars undergo large changes in luminosity and temperature with age, the observable integrated light of a galaxy also changes with time. How, for example, has the extremely distant galaxy 3C295 (now redesig- nated 1410+5224), mentioned in Year Book 59, changed in the five billion years since the observed light that fell on the Palomar photographic plate left the galaxy? Answers to questions like these will be obtained only from studies such as those undertaken by Baum and other Staff Members of the Observatories on stellar properties and evolution.

The Department of Embryology

Although the Department of Embryology was not estab- lished until 1914, when it was organized by Franklin P. Mall, 1905 even its subject was not ignored among the activities of the Institution in 1905. In that year L. B. Mendel of Yale University was given a grant for " Study of physiology of growth, especially in its chemical processes/ ' Professor Mendel's grant was renewed in each of several years thereafter. He reported that he was studying the " chemical composition of the developing animal body and the equipment of this organism for its nutrition, upon which growth essentially depends. Data are being collected at first hand regarding the composition of various embryonic tissues at different stages of embryonic growth. For the nervous system a correlation between morphological and

49 Light year — the distance traveled by light in a vacuum during one year; about 5.88 X 1012 miles.

REPORT OF THE PRESIDENT 63

chemical development is already apparent. The chemistry of embryonic muscle is also already under investigation. "The purin content of the liver and muscles at various embryonic stages has been determined. ... It is hoped ... to ascertain whether the purin metabolism of the young is essentially different from that of the adult."50 A grant to L. E. Griffin was also made in the same year "to secure material for a study of the embry- ology, histology, and physiology of the Nautilus." Studies supported at the Marine Biological Laboratory, Woods Hole, Massachusetts, included one on the "segmentation of certain fertilized eggs"; on "regenerative processes and structures"; and on "muscle-fibers of the fish heart."

These studies, however, were not in any sense an organized group. Nor did they command a major interest on the part of the Institution's admin- istration, as was shown by the termination of this type of grant at the end of 1908. It remained for Dr. Mall to set in 1914 the lines on which the Department continued so long, an examination of the morphology and histology of the human embryo and the embryonic physiology of primates. Even at the beginning of the Department, however, other organisms were studied, as illustrated by the 1914 study of E. L. and E. R. Clark on the movements of the lymph heart in living chick embryos, and their report in that year "that the muscle of the lymph heart is derived from the myotomes."51

The year 1961-1962 was marked by the setting of an im- portant milestone in the history of the Department. After 1961 1962 several years of preparation the new Department of Embry- ology building, adjacent to the Homewood Campus of the Johns Hopkins University in Baltimore, Maryland, was completed. This building, specially designed for embryological research, should free the staff of the Department from the inconveniences that attended work in their former cramped quarters at the Johns Hopkins Medical School near the center of the city. The Department started to move on August 1, 1961, and was able to assume full operation by early November, in spite of a long delay in equipping the building because of an electricians' strike. The new building appears to have met with staff ap- proval. Director J. D. Ebert describes it as having "an unusual combination of fine qualities, pleasing to both aesthetic and practical senses."

The Department in 1961-1962 is described by Dr. Ebert in the introduc- tion of his report of this year as one holding to its "traditional organization of a group of independent investigators whose interests range widely from biochemistry and microbiology to anatomy and physiology, with sub- stantial overlapping in experience and approach. ... in developmental

60 Year Book 4, pp. 259-260.

51 Year Book 13, p. 112. A myotome is a muscle mass in a developing animal.

64 CARNEGIE INSTITUTION OF WASHINGTON

biology today it appears to favor the generation and interchange of ideas. . . ."

The multifaceted program Dr. Ebert describes included an interesting study of the physiologic aspect of frog-embryo growth from the stage of the fertilized egg onward by D. D. Brown and J. D. Caston, the nature of the testicular antigen in induced aspermatogenesis52 by G. L. Carlson and D. W. Bishop, the role of deoxyribonuclease II during the metamorphosis of the tadpole by J. R. Coleman, a comprehensive study of the developing human eye by R. O'Rahilly, and still others.

Of particular interest among these was the Brown-Caston study of the embryonic development of the frog Rana pipiens. They found that the early embryos contain a measurable but small population of ribosomes in their cells. The early ribosomal content changes little until a stage near the end of morphogenesis,53 when there is a very rapid appearance of more particles. This coincides with the time when the embryo has been shown to require magnesium ions from outside. In addition, the iron storage molecule, ferritin, was definitely identified in the egg. Also, although ribosomal synthesis was shown to begin after much of morphogenesis is completed, high-molecular-weight RNA, with a base composition identical to ribosomal- ion RNA, was found to be present in all stages of the embryo.

Perhaps the most striking progress to be reported from the Department during the year came in the studies of I. R. Konigsberg, who joined the Institution as a Staff Member on July 1, 1961. They will be described in some detail as an illustration of the methods and approach of the present- day Department.

From its beginning the Department of Embryology has numbered, among its Staff Members, investigators dedicated to the study of the development, structure, chemistry, and physiology of muscles. W. H. and M. R. Lewis (Department of Embryology, 1915-1940) pioneered in analyzing the origin of muscle fibrils in tissue culture; and Arpad Csapo (1949-1954) was among the first students of muscle chemistry to characterize the contractile pro- teins of the uterus and to examine their regulation under different physio- logical conditions. More recently J. D. Ebert and R. L. DeHaan and their associates have focused attention on the biochemistry of developing con- tractile proteins and on morphogenetic movements and relations of contractile and conductile cells in the heart. D. W. Bishop has contributed importantly to our understanding of mechanisms in primitive contractile systems like sperm tails.

To this roster the Department now adds Konigsberg's name. During the year he made substantial progress in a hitherto refractory subject, the

62 Destruction of the power to produce sperm.

63 The emergence of the specific structure of an animal during embryonic development.

REPORT OF THE PRESIDENT 65

investigation of the cytodifferentiation of embryonic skeletal muscle cells in dispersed cell culture. His system of culture is designed to offer greater opportunity for rigorous control of both the quantitative aspects of the cellular population and the extracellular environment than can be achieved either in vivo or in organ culture. Many years' experience by numerous previous investigators suggested that such culturing techniques could be expected to promote the loss of differentiative character and would not favor a progressive increase in the effects of cell specialization on mor- phology. No generally satisfactory explanation for this previously observed incompatibility has ever been given. However, Konigsberg's results with monolayer cultures of embryonic skeletal muscle cells are in striking dis- agreement with expectations from earlier experience.

Monolayer cultures prepared from suspensions of 11- to 12-day chick embryonic leg muscle pass through three recognizable phases. The period immediately following plating of the cells is marked by rapid proliferation with a mean generation time of 24 hours. During this period cultures consist exclusively of mononucleated cells and have the general appearance of cultures of "fibroblast-like"54 cells such as might be derived from a great variety of tissues. The transition from the first to the second phase occurs in a matter of hours and is characterized by the formation of long multinuclear "ribbonlike" cells. Formation of these multinuclear cells coincides with the attainment of cell confluence in the culture. The effect of cell density is further suggested by experiments in which the inoculum size was varied. The smaller the inoculum, the greater the time of transition from phase one ("fibroblast-like" cell) to phase two (multinuclear "ribbon"), and vice versa. The abrupt appearance of multinucleated myotubes55 in this second phase is paralleled by an equally abrupt break downward in the rate of proliferation. Again, the time required for this development can be shifted by varying the inoculum size.

Differentiation beyond the stage of the mononucleated myoblast56 occurs in culture after cells have ceased rapid multiplication. This observation is consistent with Konigsberg's earlier findings, as well as with those from several laboratories, that myotube nuclei are postmitotic57 and that they form by cellular fusion. The third phase of muscle differentiation in culture is characterized by the progressive development of the cross-striated myofibrillar pattern and the initiation of the spontaneous contraction char- acteristic of muscular tissue.

All Konigsberg's studies before the past year had been restricted to mono-

64 Fibroblasts — elongated mononuclear cells which develop into and are also part of connective tissue.

65 Aggregated-cell constituent of muscle.

66 Unassociated single "premuscle" cell.

67 Mitosis is cell division.

66 CARNEGIE INSTITUTION OF WASHINGTON

layer cultures established with inocula of 1 million to 2.5 million cells each. Such cultures reach confluence between the second and fourth day of culture, depending on the size of the inoculum. To probe for the lower limit of inoculum size that would still permit differentiation to occur he turned to the single-cell plating technique developed by T. T. Puck and his associates. In this procedure small numbers of cells are dispersed over a relatively large area. During appropriate periods of incubation the individual cells give rise to discrete colonies visible to the naked eye. The technique has been applied most successfully to permanently established cell strains.

Using freshly isolated embryonic muscle cells Konigsberg observed a plating efficiency of approximately 10 per cent. In plates cultivated for 10 to 13 days approximately 1 in 10 colonies exhibited unmistakable signs of skeletal muscle cell differentiation. The proportion of differentiated cells ranged from colonies containing several elongated myotubes in colonies of predominantly mononucleated cells to colonies in which virtually every nucleus was in syncytial58 association. Under polarized light or bright-field illumination after staining, the myotubes showed the presence of longitu- dinal fibrils, which frequently exhibited the pattern of cross striation typical of mature skeletal muscle cells. It is apparent that some myoblasts, at least, through a sequence of rapid multiplications, can produce a large number of progeny that retain the capacity for differentiation.

Two major questions emerged from these observations. First, what is the significance of the finding that only 1 in 10 colonies eventually differentiates? Second, what is the stimulus initiating myotube formation? Konigsberg is attacking the second problem by examining the relationship of cell density to myotube formation. Two general mechanisms by which cell density might affect myotube formation were considered. Since myotube formation is a result of cell fusion, high cell density might ensure that a sufficient number of effective cell-to-cell collisions occur. Another, and equally likely, possibility is that a high cell density may be either supplementing the culture medium with cell products or removing some components.

Konigsberg designed experiments to test that possibility. His first tests showed that the medium is altered by the metabolic activity of cells cultured in it. In cultures grown on a medium preconditioned by the pres- ence of other cells, myotube formation commenced as much as 24 hours earlier than initial cultures of equal numbers of cells from the same cell suspension but cultured in fresh medium. Furthermore, the cells in condi- tioned medium attached to the glass more firmly, presenting a strikingly different appearance from the control cultures.

These results are impressive in themselves, and indeed they represent something of a technical breakthrough in the difficult task of cell culture.

58 Referring to a multinucleated aggregate of imperfectly separated cells, or a multinuclear cell.

REPORT OF THE PRESIDENT 67

But as so often in science they are probably more important for the questions they raise than for the results they give. Already they have pointed the way to a number of additional experiments to probe the relation between condi- tioned media and cell differentiation. But in the hint given of a hitherto unsuspected closeness of relation between cell and environment we touch a problem of wide application and perhaps vast significance in understanding all higher forms of life.

Although a report describing work like Konigsberg's can give something of the sense of high adventure experienced by scientists within the Institu- tion and elsewhere, there are dimensions to the scientific life of today that must always escape any progress report. Most of those who work within the Institution share a deep conviction about the humanity of their calling and about the community of fellowship that not only is vital to the progress of their work but also is a deeply felt reward in itself. Happily these convic- tions occasionally shine through more esoteric daily concerns. They are notable this year in the comments of James Ebert and Merle Tuve, each on a point of his philosophy.

Ebert has written particularly of his own deep attachment to the essential unity of living science. He quotes Frank R. LilhVs memorable words that " Scientific discovery is a truly epigenetic process in which the germs of thought develop in the total environment of knowledge." The life of the laboratory, where one must be quick to acknowledge what has gone before, alert to the current actions of others having similar interests, and mindful of the needs for others to know, can be a social experience almost beyond comparison. Dr. Ebert notes his pleasure at having visiting investigators from other institutions: "They do contribute vitally to the Department . . . but of far greater moment is the question whether such a visit adds measur- ably to the man's ability as an investigator and teacher when he returns to his home laboratory. Has he found new direction or meaning for his re- search? Has the opportunity for reflection. . . led to a searching reexamina- tion of his program?" With pride, the Institution can record that its Departments provided literally hundreds of such opportunities during the year.

Tuve's comments touch upon the aesthetic experience of being a scientist, and upon what is perhaps one of the deepest motivations in "exact" science. Contrasting it with the disorder and transience he sees in the life of men in the mass, he expresses his admiration at "the beautiful regularity and systematic relatedness. . . in every aspect of the natural phenomena. . . from distant stars to living bacteria." He considers this a cause of the sense of very deep satisfaction in scientific studies. Through science, man, bit by bit,

68 CARNEGIE INSTITUTION OF WASHINGTON

is adding to his stature and to "his awe of the stupendous and beautifully intricate universe in which he finds himself." Tuve considers it a "great good fortune" for scientists to be able to devote their energy and talents to illuminating "the intricate and orderly patterns of the physical world around us." To him this is "a princely gift of our time and circumstances."

Such motivations lead to a dedication which is the wonder of all who have not experienced their attractions. It is a dedication measured only in part by a voluntary 70-hour week, by long nights on a mountaintop in below-freezing weather, by a hundred frustrations with equipment design, or by a willing- ness to work at the modest salaries that fundamental science is able to provide. We can hope that Andrew Carnegie, after sixty years, might be approving of both the dedication and the insights of these men and their predecessors as they have striven "to secure, if possible, for the United States of America leadership in the domain of discovery. . . of new forces."59

Losses . . .

I must report with great sorrow the loss of a devoted member of the Board of Trustees, the Honorable Robert Woods Bliss, and of a highly valued Staff Member of the Mount Wilson and Palomar Observatories, Don 0. Hendrix.

Robert Woods Bliss, a Trustee of the Institution for twenty-six years, died in Washington, D. C, on April 19, 1962. Elected a Trustee in 1936, he became a member of the Executive Committee the following year. He was Secretary of the Board of Trustees from 1953 until his death. He also served continuously from 1939 on the Committee on Archaeology, from 1939 to 1945 on the Auditing Committee, and from 1950 to 1953 and 1958 to 1961 on the Nominating Committee.

Before his association with the Institution he had already had a distin- guished career of 33 years in the diplomatic corps of the United States, where he held many important posts. He was especially concerned with efforts to bring about world security through arms control and international organization. In 1908 he was United States delegate to the International Conference to Consider Measures for the Revision of Arms and Ammunition Regulations in Brussels. As counselor to our embassy in Paris from 1916 to 1919 he assisted in preparations for the Versailles Peace Conference and in its work. Again, in 1921, he was a member of the United States delegation to the Washington Conference on the Limitation of Armaments. His beautiful estate, Dumbarton Oaks, in Washington, was the scene of the conference that laid plans for the United Nations.

69 Andrew Carnegie, Trust Deed Creating a Trust for the benefit of the Carnegie Institution of Washington, D. C, January 28, 1902.

REPORT OF THE PRESIDENT 69

Just before his retirement in 1933 he had served for six years as am- bassador to Argentina; and during World War II he was called back from his technical retirement to serve as special consultant and then special assistant to the Secretary of State.

Mr. Bliss will be remembered by the Washington community for his many philanthropic and cultural contributions. The Institution will remember his dedication to its welfare and his gentle but always penetrating counsel on every problem.

Another loss that is especially felt is that of Don O. Hendrix of the Mount Wilson and Palomar Observatories, who died on December 26, 1961, at the age of 57. Joining the staff of the Observatories in 1913, Hendrix became Superintendent of its optical shop in 1947, where he carried out such im- portant projects as the optical design for the 48-inch schmidt telescope and the final figuring of the 200-inch mirror after it had been moved to Palomar. His extraordinary skill was largely responsible for the high efficiency of the present equipment of the Observatories.

With keen regret I also record the loss to the Institution of four retiring members of the staff. Dr. Berwind P. Kaufmann, Director of the Depart- ment of Genetics, Dr. Robert K. Burns, Staff Member of the Department of Embryology, Mrs. Ruth L. McCollum, Assistant to the President, and Wilbur A. Pestell, Administrative Assistant at the Department of Plant Biology, all retired on June 30, 1962.

Dr. Kaufmann came to the Department of Genetics in 1937 from the University of Alabama, where he had served for ten years as professor and department head. Since that time his professional interests have touched on many facets of the broad field of cytogenetics, with emphasis on the varying patterns of chromosome structure that influence gene action. These interests stemmed from experience in the area of descriptive cytology, gained in the early 1920's, when chromosomes were generally regarded as uniformly staining rod-shaped structures with no discernibly precise pattern of internal organization. By developing and applying ingenious techniques, Dr. Kaufmann demonstrated that chromosomes contain paired, helically dis- posed strands at all phases of somatic and meiotic mitoses.

Upon joining the Institution's staff, Dr. Kaufmann undertook an analysis of the types and frequencies of chromosomal rearrangements induced by ionizing radiations, using the giant chromosomes in the salivary glands of Drosophila for diagnostic purposes. His discovery and evaluation of the effects of near-infrared radiation on the frequencies of X-ray-induced re- arrangements was an outstanding accomplishment of that period.

In 1960 Dr. Kaufmann succeeded Dr. M. Demerec, first as Acting Director and in 1961 as Director of the Department. During his twenty-five

70 CARNEGIE INSTITUTION OF WASHINGTON

years at Cold Spring Harbor he maintained a strong interest in science education and in the training of young biologists. He has now returned to a university environment, having been appointed Professor of Zoology and Senior Research Scientist at the University of Michigan, where his sincerity, dedication, and technical skill will be inspiring to those who have the good fortune to work with him.

Dr. Burns joined the Department of Embryology in 1940 from the University of Rochester, where he had been a member of the Department of Anatomy, of which Dr. George W. Corner was the head before his own move to the Institution. When he went to Baltimore, Dr. Burns rejoined Dr. Corner and another long-time Rochester colleague, B. H. Willier, who had assumed the direction of the Johns Hopkins Department of Biology. Burns, who held the title of Honorary Professor of Biology at the University, served as an important link between the two departments, pointing the way to the close association that exists today.

Dr. Burns has devoted his entire career to studying the mechanisms of sex differentiation. A student of Ross G. Harrison, he began by demonstrating sex reversal in amphibians, using the technique of embryonic parabiosis. His was the first convincing laboratory research following up Frank R. Lillie's analysis of the freemartin.60 Later he turned his attention to mammals, and again produced the first convincing evidence of sex reversal by the use of purified sex hormones in his analysis of the effects of estradiol on the pro- spective male opossum.

Dr. Burns has returned to Bridgewater College, where he received his first degree. He is teaching embryology and continuing his research on sex differentiation.

A loss most keenly felt by the President and the Office of Administration was the retirement of Mrs. Ruth McCollum, Administrative Assistant to the President. Mrs. McCollum joined the Institution staff in the administra- tive office of the Department of Terrestrial Magnetism in 1942, where she gave distinguished assistance during the difficult period of the war. In 1946 she transferred to the Bursar's office in the Office of Administration, where she served for thirteen years, first as secretary to the Bursar and then as Accountant. During the latter part of this period Mrs. McCollum con- tributed part of her time and skill to general responsibilities of the Office of Administration. Early in 1959 she became Administrative Assistant to the President. Her management of arrangements for the Annual Meeting of the Board of Trustees was always a model of organization and good taste. Her artistic talent appeared in many ways in her work, much to the Institution's advantage, as in the annual departmental exhibits. No problem was too difficult to tax her good humor, and long hours only increased her devotion

60 A modified female of bovine heterosexual twins.

REPORT OF THE PRESIDENT 71

to the Institution. Her many talents and fine spirit are much missed by all who worked with her.

Wilbur A. Pestell, Administrative Assistant at the Department of Plant Biology, also retired on June 30, 1962. He was actively associated with the Institution for 42 years, a period of dedicated service seldom equaled by past employees. He worked first in the Division of Publications in Washington, subsequently at the Desert Botanical Laboratory near Tucson, then at the Coastal Laboratory at Carmel, California, and finally as Secretary in the Department of Plant Biology at Stanford. His faithful work cleared routine tasks from the way of many others whose scientific results have been re- ported in these Year Books.

. . . and Changes . . .

The year 1962, in addition to signalizing the sixtieth anniversary of the Institution, also marked a significant change in its internal organization. Upon the retirement of Dr. Berwind P. Kaufmann, the fourth Director of the Department of Genetics, on June 30, 1962, the status of genetics re- search within the Institution was altered. As of July 1, the Department of Genetics became the Genetics Research Unit, with Alfred D. Hershey as Director. The work of the Unit will center on the research of Hershey, Barbara McClintock, and their associates at Cold Spring Harbor. In September 1962, Helen Gay, another Staff Member of the Unit, transferred her work to Ann Arbor, Michigan, where she will continue her association with Dr. Kaufmann.

The Department of Genetics was formed in 1921 from a merger of the former Department for Experimental Evolution and the Eugenics Records Office. The Department for Experimental Evolution, which was formed in 1906, had been preceded by the Station for Experimental Evolution, established at the present site in Cold Spring Harbor, New York, during 1904. The dominant traits of the Department of Genetics were clearly those it inherited from the Department for Experimental Evolution. For fifty- eight years the research groups that successively made Cold Spring Harbor their scientific home maintained a research tradition which in many ways has been the story of genetics progress in the United States. Originally con- ceived by its first Director, C. B. Davenport, and inspired by the preceding work of Hugo de Vries in the Netherlands, the Cold Spring Harbor labora- tory has had an uncanny record of association with and stimulation of the main currents in genetic thought during the more than half century of its existence. Even twenty years ago Milislav Demerec, on the eve of his be- coming the third Director of the Department, could say that the "backing

72 CARNEGIE INSTITUTION OF WASHINGTON

given to genetical research by the Institution undoubtedly accounts to a large degree for the fact that the United States now occupies the leading position in this branch of science."61

The Station's first work followed Dr. Davenport's lead. He had a con- suming ambition to prove experimentally the broad application of Mendel's law as rediscovered in 1900 by de Vries in the Netherlands, Correns in Germany, and von Tschermak-Seysenegg in Austria. Davenport's early work on poultry, birds, and mammals did actually furnish classic experi- mental confirmation of the broad application of Mendelian inheritance.

Davenport's student and later colleague G. H. Shull provided one of the most unusual chapters in the Laboratory's history by laying the theoretical foundations of hybrid corn cultivation, described by Mangelsdorf as "the most far-reaching development in applied biology of this quarter century."62 Shull's recognition and exploitation of heterosis (hybrid vigor), which he named, gave the basic principle "which underlies almost the entire hybrid corn enterprise."63 More recently the same plant in the hands of Barbara McClintock has been a highly successful medium for discovering the muta- tional behavior of genes. Both may certainly be counted among the most significant achievements in genetics.

Illustrative of the range of interests to be found in the work of the Laboratory through its fifty-eight years of history are the pioneering experi- mental studies of C. C. Little on the inheritance of tumors, followed later by E. C. MacDowell's and J. S. Potter's studies of mouse leukemia; the foundation of cytogenetics by John Belling, followed by the productive cytogenetic research undertaken on Datura (of the potato family) by A. F. Blakeslee, the second Director of the Department, and his colleagues, and succeeded more recently by B. P. Kaufmann's cytogenetic studies on Drosophila; the painstaking studies of Milislav Demerec, mapping the gene loci of Escherichia coli and Salmonella; and the work of A. D. Hershey, exploring the molecular structure of the bacterial phage chromosome.

Through the years the Department has been no less favored by geneticists who have been associated with it on a part-time basis. Among the Research Associates and Guest Investigators who were connected with the Depart- ment at one time or another in its history were: W. E. Castle, E. B. Wilson, C. B. Bridges, H. E. Crampton, E. B. Badcock, L. C. Dunn, Th. Dobzhan- sky, M. Delbrlick, A. Hollaender, D. G. Catcheside, M. Westergaard, C. Stern, and S. Brenner.

The Institution will continue support of genetics research, although at a

61 Carnegie Institution of Washington Year Book 4U P- 170.

62 Paul C. Mangelsdorf, "Hybrid corn: its genetic basis and its significance in human affairs," in Genetics in the Twentieth Century, edited by L. C. Dunn, The Macmillan Company, New York, 1951, p. 555.

63 Ibid., p. 653.

REPORT OF THE PRESIDENT 73

reduced scale by comparison with the Department's peak staff. The Genetics Research Unit will remain at Cold Spring Harbor. It is hoped that it will be joined by an interuniversity-sponsored research group investigating quanti- tative biology, the formation of which was being explored at the year's end.

. . . and Gains

Two new members were elected to the Board of Trustees of the Institution on May 11, 1962: William Walden Rubey and Carl Joyce Gilbert.

Dr. Rubey is one of the country's most distinguished geologists. From 1920 until 1960 he was associated with the United States Geological Survey, where his work received signal recognition in the Award of Excellence of the Department of the Interior in 1943 and the Distinguished Service award in 1950. His contributions have added significantly to scientific understanding in several fields of geology, notably in knowledge of the original formation of the oceans, the transport of particles and sediments by running water, and the mechanics of very large overthrust faults. He is a graduate of the University of Missouri and holds honorary doctoral degrees both from that University and from Yale. At present he is serving as a member of the National Science Board (National Science Foundation) and of the board of directors of the American Association for the Advancement of Science.

Mr. Gilbert is Chairman of the Board, Gillette Company, Boston. He is a graduate of the University of Virginia and the Harvard Law School. He is a member of the board of directors of several corporations, including the Raytheon Manufacturing Company, the Fiduciary Trust Company, and the Pepperell Manufacturing Company. Devoted to public service as well as to business, Mr. Gilbert is a member of the board of managers and past presi- dent of the Boston Dispensary, vice-chairman of the Massachusetts Port Authority, trustee of the New England Center Hospital, member of the administrative board of the New England Medical Center, vice-president of the New England Council, and trustee and member of the executive committee of Tufts College. Before he became chairman of the board of the Gillette Company in 1958 he had served as its president.

It is always a special pleasure to record the honors that have come to members of the Institution.

Presentation of the Kettering award for 1961 to Dr. Vannevar Bush, retired President of the Institution, was made at a conference in Washing- ton, D. C, of the Patent, Trademark, and Copyright Foundation of George Washington University for outstanding work in the field of patents, trade- marks, and related areas.

74 CARNEGIE INSTITUTION OF WASHINGTON

At the Mount Wilson and Palomar Observatories, Ira S. Bowen, the Director, was elected a member of the Royal Society of Sciences of Uppsala, Sweden. The Newcomb Cleveland prize of $1000 was awarded to Halton C. Arp, Staff Member, on December 29, 1961, by the American Association for the Advancement of Science for "a noteworthy paper, representing an outstanding contribution in science.' ' Robert P. Kraft, Staff Member, re- ceived the Helen B. Warner prize of the American Astronomical Society for outstanding research by a young member of the Society. Guido Munch and Allan R. Sandage, Staff Members, were elected fellows of the American Academy of Arts and Sciences. Fritz Zwicky, Staff Member, was elected a member of the International Academy of Astronautics. This organization, which is only a year old, is the first international academy of scientists and engineers who have made contributions to space technology. It is limited to 165 active members in the life sciences, basic sciences, and engineering.

At the Geophysical Laboratory, Philip H. Abelson, the Director, received on April 6, 1962, the Washington State University Regents' Distinguished Alumnus award for the academic year 1961-1962.

Scott E. Forbush, Staff Member of the Department of Terrestrial Magnetism, was elected to membership in the National Academy of Sciences, April 24, 1962, and on June 14, 1962, he received an honorary doctor of science degree from Case Institute of Technology, Cleveland, Ohio, for his contributions to our understanding of cosmic-ray phenomena.

At the Department of Plant Biology, Jens Clausen, retired Staff Member, was made a Knight of the Order of Dannebrog by the King of Denmark in recognition of his contributions to botany and genetics. The Danish consul presented the decoration to Dr. Clausen on October 13, 1961, in San Francisco.

M. Demerec, retired Director of the Department of Genetics, was awarded the Kimber Genetics medal of the National Academy of Sciences on April 24, 1962, "in recognition of his many contributions to the understanding of the genetics of various plants, Drosophila, bacteria, and viruses, and especially for his leadership in the investigation of unstable genes, the mutation process, genetics of micro-organisms and the genetic fine structure of the gene."

J. E. S. Thompson, retired Staff Member of the Department of Archae- ology, received the honorary degree of doctor of humane letters and the Drexel Medal for Archaeology from the University of Pennsylvania in February 1962.

Scientists and Scholars, 1902 - 1962

In essence, the whole quality of the Institution, and its history, lie with those who have been associated with it over the years. Following are the names of the senior scientific staff members of all departments of the Institution over the last fifteen years (or over the last fifteen years of the existence of terminated departments). Below them in each department are listed the names of eminent and representative scientists and scholars who have been members of the staff or otherwise affiliated with the Institution since it was founded in 1902. A list is also given of all Fellows of the Carnegie Institution of Washington since the beginning of its Fellowship Program in 1947, and a list of grantees and others affiliated with the Institution but not with any particular department.

75

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CARNEGIE INSTITUTION OF WASHINGTON

DEPARTMENT OF PLANT BIOLOGY

Desert Laboratory, opened in 1903, became headquarters of Department of Botanical Research in 1905; name changed to Laboratory for Plant Physiology in 1923; reorganized in 1928 as Division of Plant Biology, including ecology; name changed to Department of Plant Biology in 1951.

Directors

Daniel T. MacDougal, 1906-1927

Herman A. Spoehr, 1927-September 1930, September 1931-1947 {Chairman)) 1947-1950

{Chairman Emeritus)

C. Stacy French, 1947—

Staff Members

Jeanette S. Brown, 1958 — Jens C. Clausen, 1931-1956 David C. Fork, 1961 — Paul Grun, 1949-1954 William M. Hiesey, 1926— David C. Keck, 1928-1951

Donald W. Kupke, 1955-1956 Harold W. Milner, 1927— Malcolm A. Nobs, 1939-1941, 1951- James H. C. Smith, 1925-1961 Harold H. Strain, 1927-1962 Ellen C. Weaver, 1961-1962

Violet (Koski) Young, 1949-1953

John Belling, 1921-1933 William A. Cannon, 1903-1924 Frederic E. Clements, 1917-1941 Waldo S. Glock, 1931-1938 Harvey M. Hall, 1918-1932

Garrett J. Hardin, 1942-1946 Burton E. Livingston, 1906-1909 Francis E. Lloyd, 1906 Winston M. Manning, 1941-1946 Forrest Shreve, 1908-1945

Godfrey G. Sykes, 1906-1929

Other Scientists and Scholars Associated with the Department

Leroy R. Abrams, 1932

(Stanford University) Ernest Anderson, Research Associate

1932-1936 (University of Arizona) William A. Arnold, Research Associate

1956-1961

(Oak Ridge National Laboratory) Eric Ashby, 1930

(Clare College, Cambridge University) Daniel I. Axelrod, 1937, 1939, 1944, 1950, 1959

(University of California) Ernest B. Babcock, Research Associate

1926-1945 (University of California) Irving W. Bailey, Research Associate

1928-1930, 1932-1939

(Harvard University) Charles E. Bessey, 1914

(University of Nebraska)

Nathaniel L. Britton, Research Associate

1902, 1912-1916, 1918-1922

(New York Botanical Garden) Ursula Brodfiihrer, 1956

(University of Munich) Douglas H. Campbell, 1911

(Stanford University) Ralph W. Chaney, Research Associate

1923-1956

(University of California, Berkeley) William S. Cooper, 1919-1925

(University of Minnesota) Frederick V. Coville, 1902-1905

(U. S. Department of Agriculture;

later, U. S. National Museum) Pierre Dansereau, 1949

(University of Montreal; later,

New York Botanical Garden)

REPORT OF THE PRESIDENT

77

John P. Decker, 1957

(U. S. Forest Service) Lee R. Dice, Research Associate

1929-1930, 1932-1934-1938

(University of Michigan) Erling Dorf, 1930, 1936, 1942

(Princeton University) A. E. Douglass, Research Associate

1924-1938 (University of Arizona) Newton B. Drury, Research Associate

1937-1942

(California State Parks Commission) Benjamin M. Duggar, Research Associate

1920-1921 (Missouri Botanical Garden;

later, University of Wisconsin) Friedrich Ehrendorfer, 1951-1952

(University of Vienna) Robert Emerson, Research Associate

1937-1941

(California Institute of Technology) G. E. Erdtmann, 1930

(University of Stockholm) William G. Farlow, 1905

(Harvard University) Edward E. Free, Research Associate, 1920

(U. S. Department of Agriculture) Martin Gibbs, 1962 (Cornell University) John W. E. Glattfeld, Research Associate

1920-1921 (University of Chicago) Richard H. Goodwin, 1950

(Connecticut College) Verne E. Grant, 1949-1950

(Rancho Santa Ana Botanic Garden) Helen M. Habermann, 1959

(Goucher College) Per Halldal, 1955-1957 (University of Oslo) Francis T. Haxo, 1957

(Scripps Institution of Oceanography) Robert Hill, 1952 (Cambridge University) A. Stanley Holt, 1959

(National Research Council of Canada) Ellsworth Huntington, Research Associate in

Geology, 1903-1904, 1910-1912, 1915-1917,

1922-1923 (Yale University) Donald A. Johansen, 1931-1932

(private research) Ivan M. Johnston, 1942 (Harvard University) Erik G. J0rgensen, 1959

(Royal Danish School of Pharmacy) Robert W. Krauss, 1951-1955

(University of Maryland) Elias Landolt, 1953-1955

(Swiss Federal Institute of Technology)

Charlton M. Lewis, Research Associate

1938-1941 (Patent Agent,

Barkelow and Lewis, Pasadena) Harlan Lewis, 1954-1955

(University of California, Los Angeles) Esmond R. Long, 1914-1915

(University of Chicago; later, Henry Phipps

Institute, University of Pennsylvania) John M. Macfarlane, 1902

(University of Pennsylvania) Axel Madsen, 1962 (Royal Veterinary

and Agricultural College, Copenhagen) Herbert L. Mason, 1925

(University of California) Max Milner, 1957 (UN Children's Fund,

Food Conservation Division) George T. Moore, 1914

(Missouri Botanical Garden, St. Louis) Vladimir Moravek, Research Associate, 1926

(University of Brno, Czechoslovakia) Jack E. Myers, 1950-1951, 1959

(University of Texas) Hedda Nordenshiold, 1949

(Royal Agricultural College, Uppsala) Axel Nygren, 1950

(Royal Agricultural College, Uppsala) Winthrop J. V. Osterhout, Research Associate

1922-1924 (Harvard University; later,

Rockefeller Institute for Medical Research) James B. Overton, Research Associate

1903, 1926-1927 (University of Wisconsin) George J. Peirce, 1910-1912

(Stanford University) Gifford Pinchot, 1902

(U. S. Department of Agriculture; later,

Yale University and Governor of

Pennsylvania) Thomas R. Pray, 1960-1961

(University of Southern California) Joseph N. Rose, Research Associate

1908, 1910-1923 (U. S. National Museum) Gilbert M. Smith, Research Associate

1926-1927 (Stanford University) Roger Y. Stanier, 1959

(University of California, Berkeley) G. Ledyard Stebbins, Jr., 1934-1936, 1945

(University of California, Davis) Bernard Strehler, 1955 (National Heart

Institute, Baltimore City Hospital) Walter T. Swingle, 1904

(U. S. Department of Agriculture) Hiroshi Tamiya, 1952-1953 (Tokugawa

Institute for Biological Research)

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CARNEGIE INSTITUTION OF WASHINGTON

Edwin W. Tisdale, 1959 (University of Idaho) Sam F. Trelease, 1914 (Columbia University) Vladimir tJlehla, Research Associate, 1924

(University of Brno, Czechoslovakia) Cornelius B. Van Niel, 1931-1932

(Stanford University) Chakrauarti S. Venkatesh, 1955-1956

(Forest Research Institute, India) Wolf Vishniac, 1957 (Yale University;

later, University of Rochester) Diter von Wettstein, 1959

(University of Copenhagen)

Heinrich Walter, 1929

(University of Stuttgart) John E. Weaver, Research Associate

1922-1930 (University of Nebraska) George R. Wieland, Research Associate

1903-1934, 1941 (Yale University) Ira L. Wiggins, Research Associate

1932-1933, 1936 (Stanford University) Paul C. Wilbur, 1926-1927 (Food Machinery

and Chemical Corporation, San Jose) S. W. Williston, 1904 (University of Chicago) Frederick T. Wolf, 1960

(Vanderbilt University)

MOUNT WILSON AND PALOMAR OBSERVATORIES

Mount Wilson Observatory organized in 1904; unified operation with the Palomar Observatory of the California Institute of Technology began in 1948.

Directors

George E. Hale, 1904-1923; 1923-1936 (Honorary)

Walter S. Adams, 1924-1945

Ira S. Bowen, 1946—

Staff Members

Halton C. Arp, 1957— Walter Baade, 1931-1958 Harold D. Babcock, 1909-1948 Horace W. Babcock, 1946—