Popular Science Monthly/Volume 74/April 1909/Life and Works of Darwin

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THE

POPULAR SCIENCE

MONTHLY

 

APRIL, 1909




LIFE AND WORKS OF DARWIN[1]
By Dr. HENRY FAIRFIELD OSBORN

COLUMBIA UNIVERSITY AND THE AMERICAN MUSEUM OF NATURAL HISTORY

I

COLUMBIA UNIVERSITY is celebrating the hundredth anniversary of the birth of Darwin, the fiftieth anniversary of the publication of the "Origin of Species." In the year 1809 many illustrious men[2] were born, among them Darwin and Lincoln, one hundred years ago to-day, February 12. So widely different in their lives, Darwin and Lincoln were jet alike in simplicity of character and of language, in love of truth, in abhorrence of slavery, and especially in unconsciousness of their power. Both were at a loss to understand their influence over other men. "I am nothing and truth is everything," once wrote Lincoln. In concluding his autobiography Darwin wrote:

With such moderate abilities as I possess, it is truly surprising that I should have influenced to a considerable extent the belief of scientific men on some important points. My success as a man of science has been determined as far as I can judge, by complex and diversified mental qualities and conditions. Of these, the most important have been, the love of science, unbounded patience in long reflecting over any subject, industry in observing and collecting facts, a fair share of invention as well as of common sense.

Lincoln's greatest single act was his death blow to slavery. Man had been fighting for centuries for his freedom, in labor, in government, in religion, and in mind. It is certainly notable that the final victory for bodily liberty was won during the "very years which witnessed the final emancipation of the mind. I do not see that Darwin's supreme service to his fellow men was his demonstration of evolution—man could have lived on quite as happily and perhaps more morally under the old notion that he was specially made in the image of his maker. Darwin's supreme service was that he won for man absolute freedom in the study of the laws of nature; he literally fulfilled the saying of St. John, "Ye shall know the truth, and the truth shall make you free."

When we look back upon the very recent years of 1858-59, the years of revolution, we see that we were far from free either to-study nature or reason about it. Our intellectual chains were from the forges of theology both catholic and protestant. The Bible was read as a revelation of physical law rather than as an epic of righteousness and spiritual law. Theology while in power was itself in a most critical position, in a cul-de-sac of antagonism to reason and common sense, and this despite the warnings of Augustine and of Bacon. As early as the fifth century the wise theologian of Numidia had said:

Leave questions of the earth and the sky and the other elements of this world to reasoning and observation. Perceiving that you are as far from the truth as the east from the west the man of science will scarce restrain his laughter.

Similarly, the great founder of the inductive method observed:

Do not excite the laughter of men of science through an absurd mixture of matters human and divine. Do not commit the consummate folly of building a system of natural philosophy on the first chapter of Genesis or on the Book of Job.

It is difficult for the college student in this day of liberty, if not of license, to realize that, in the words of Lowell:

We breathe cheaply in the common air thoughts that great hearts once broke for.

When, in 1844, Darwin communicated to the botanist Hooker under promise of secrecy his outline of evolution, he well knew the opprobrium it would bring, for he subsequently added (1846):

When my notes are published I shall fall infinitely low in the opinion of all sound naturalists, so this is my prospect for the future.

From the borders of Poland in 1543, or just three centuries earlier, Copernicus had published his "Revolutions of the Heavenly Bodies," and thus fired the first shot in a three-hundred-years war for freedom to observe nature. In 1611 the telescope of Galileo demonstrated the truth of the Copernican law that the earth moves around the sun; and the most impressive object to-day in Florence is the model of the finger of this great astronomer as he held it up before the examiners of the inquisition, with the words, "It still moves."

As time advanced the prison gave way to the milder but effective
 
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weapons of ostracism and loss of position. In biology Linnæus, Buffon, Lamarck, St. Hilaire, in turn discovered the evidences of evolution, but felt the penalty and either recanted or suffered loss of position. The cause of supernaturalism had never seemed stronger than in 1857; the masterly works of Paley and Whewell had appeared; the great series of Bridgewater Treatises to demonstrate the wisdom and goodness of God in the special creation of adaptations had just been closed; men of rare ability, Cuvier, Owen, Lyell and Agassiz, were on the side of special creation; yet at the very time this whole system of natural philosophy was rotten at the foundation because not the work of free observation.

Where his great predecessors Buff on and Lamarck had failed, Darwin won through his unparalleled genius as an observer and reasoner, through the absolutely irresistible force of the facts he had assembled and through the simplicity of his presentation. Lacking the literary graces of his grandfather, Erasmus Darwin, and the obscurity of Spencer, Darwin was understood by every one as every one could understand Lincoln. It is true the cause was immediately championed by able men, but victory was gained not by the vehement and radical Haeckel nor yet by the masterly fighter Huxley, but through the resistless power of the truth as Darwin saw it and presented it. It was not a denial, as had been the great skeptical movement of the end of the eighteenth century, but an affirmation. Darwin was not destroying but building; yet at the time good and honest men trembled as if passing through an earthquake, for in the whole history of human thought there had been no such cataclysm.

 
II

In what he achieved Darwin is so entirely alone that his place in the history of ideas is next to Aristotle, the great Greek biologist and philosopher who preceded him by over 2,000 years.

The biographers of Lincoln are at a loss to explain his greatness through heredity. Darwin belonged to an able family, and his ancestors are singularly prophetic of his career. He was near of kin to Francis Galton, who shares with Weismann the leadership in the study of heredity during the nineteenth century. By a happy combination of all the best traits of the best of his ancestors coupled with the no less happy omission of other traits, Darwin was a far greater man than any of his forebears. Kindliness, truthfulness and love of nature were part of his birthright. From his grandfather Erasmus, Charles may have inherited especially his vividness of imagination and his strong tendency to generalize. Countless hypotheses flitted through his mind.[3] "Without speculation there is no good and original observation," he wrote to Wallace. Still more interesting is the fact that the inheritance of his grandfather's tendency toward speculation took the direction of evolution, for before the close of the eighteenth century Erasmus Darwin gave the world in poetical form his belief in a complete evolutionary system as well as the first clear exposition of what is now known as the Lamarckian hypothesis. But in the grandson hypotheses were constantly held in check by the determination to put each to the severe test of observation. Darwin speaks of his father, Robert, as the most acute observer he ever saw, and attributes to him his intense desire to understand the reasons of things; from him came caution and conservatism. He says in his "Autobiography":

I have steadily endeavored to keep my mind free so as to give up any hypothesis (however much beloved), and I can not resist forming one on every subject, as soon as facts are shown to be opposed to it.

If the "poet is born not made," the man of science is surely both born and made. Bare as was Darwin's genius, it was not more rare than the wonderful succession of outward events which shaped his life. It is true that Darwin believed with his cousin Francis Gal ton that education and environment produce only a small effect upon the mind of any one, but Darwin underestimated the force of his educational advantages just as he underestimated his own powers, and this because he thought only of his book and classroom life at school, at Edinburgh and at Cambridge, and not of his broader life. It was true in 1817, as to-day, that few teachers teach and few educators educate. It is true that those were the dull days of classical and mathematical drill. Yet look at the roster of Cambridge and see the men it produced. From Darwin's regular college work he may have gained buit little, yet he was all the while enjoying an exceptional training. Step by step he was made a strong man by a mental guidance which is without parallel, by the precepts and example of his father, for whom he held the greatest reverence, by his reading of the poetry of Shakespeare, Wordsworth, Coleridge and Milton, and the scientific prose of Paley, Herschel and Humboldt, by the subtle scholarly influences of old Cambridge, by the scientific inspiration and advice of Henslow, by the masterful inductive influence of the geologist Lyell, and by the great nature panorama of the voyage of the Beagle.

The college mates of Darwin saw more truly than he himself what the old university was doing for him. Professor Poulton of Oxford, believes that the kind of life which so favored Darwin's mind has largely disappeared in English universities, especially under the sharp system of competitive examinations; yet this is still more truly the atmosphere of old Cambridge to-day than of any of our American colleges. It would be an interesting subject to debate whether we
 
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could nurture such a man; whether a Darwin, were he entered at a Columbia, a Harvard, a Princeton, could develop mentally as Charles Darwin did at Cambridge in 1817. I believe that conditions for the favorable nurture of such a mind are not with us. They are, repose, time for continuous thought, respect for the man of brains and of individuality and of such peculiar tastes as Darwin displayed in his avidity for collecting beetles, freedom from mental convention, general sympathy for nature, and above all ardor in the world of ideas. If the genial mind can not find the kindred mind it can not develop. Many American school and college men are laughed out of the finest promptings of their natures. In short I believe our intellectual environment would be distinctly against a young Darwin to-day.

Thus event after event in Darwin's life was singularly propitious. None but a Darwin would have reflected these events as he did, but grand and rare they certainly were.

At the age of nineteen he entered Christ's of Cambridge, the small college which two hundred years before had sheltered John Milton, the great poet of "Paradise Lost," the epic of the special creation theory which it was Darwin's destiny to destroy. His passion for sport, shooting, hunting, cross country riding, his genial enjoyment of friends of his own age, did not prevent delightful excursions with older men. He was known as "the man who walks with Henslow"; and close personal intercourse with this learned and genial botanist (Eev. Wm. C. Henslow) affected him more than any other feature of his college life. After graduation this personal association extended through Henslow to the geologist Sedgwick, who prepared him for the next step in his career. It was Henslow who secured for him his place on the exploring ship Beagle and the voyage round the world (1831-1836), by far the most important experience in his life.

No graduate course in any university can compare for a moment with the glorious vision which passed before young Darwin on the Beagle, but here again fortune smiled upon him, for this vision required the very scientific spirit and point of view which came to him through the reading of the "Principles of Geology" of Lyell, the masterly teacher of the uniformitarian doctrine of Hutton. That nature worked slowly in past as in present time, and that the interpretation of the past is through observation of the present gave the note of Darwin's larger and more original interpretation, because the slow evolution which Lyell piously restricted to geology and the surface of the earth Darwin extended to biology and all living beings. If during the voyage Lyell's arguments convinced Darwin of the permanence of species, Lyell's way of looking at nature also gave him the means of seeing that species are not permanent. In his own words, he "saw through Lyell's eyes," and with the admiration of others always so characteristic of him his tribute to Lyell is without reserve. The second edition is dedicated:

With grateful pleasure as an acknowledgment that the chief part of whatever scientific merit this Journal and the other works of the author may possess has been derived from studying the well known and admirable "Principles of Geology."

The five years of the voyage filled the twenty-second to twenty-seventh years of Darwin's life, the period now ordinarily given to professional studies. In reading this simply written but fascinating book, which stands quite by itself in literature, we see how Darwin through his own genius and through the methods successively impressed upon him by his father, by Henslow, by Sedgwick and by Lyell was unconsciously preparing his mind for the "Origin of Species" and the "Descent of Man," the two most influential books of science which have ever appeared. From the islands of the Atlantic and the Pacific we follow his delightful comments on animals and plants of all kinds on sea and land, through forests, pampas and steppes, up the dry slopes of the Andes, along the salt lakes and deserts of Chili and of Australia. The dense forests of Brazil pendent with orchids and gay with butterflies contrast with those of Terra del Fuego and of Tahiti, and with the deforested Cape de Verde Islands. On these islands, the first he visits, he is enormously impressed by the superiority of Ly ell's method. He visits other islands of all kinds, inhabited and uninhabited, the non-volcanic St. Paul's rocks, half-submerged volcanic cones, coral reefs and islands of the south Pacific. He observes live glaciers, as well as the contrasting action of active and of dead volcanoes. Along the rivers of Patagonia he unearths great extinct or fossil mammals; in Peru he studies the extinct races of man; the aborigines of Terra del Fuego and of Patagonia make the most profound impression upon his mind. In brief, he sees the great drama of nature in all its lesser scenes and in all its grander acts. He begins the voyage a firm believer in the fixity of species, but doubts begin to enter his mind when in the sands of the pampas of South America he perceives that the extinct forms are partly ancestral to the living, and when on the isolated Galapagos Islands he finds the life is not that of a special creation but that detached from the continent of South America six hundred miles distant.

Darwin says:

I owe to the voyage the first real training and education of my mind. That my mind had developed is rendered probable by my father's first exclamation on my return, "why the shape of his head is quite altered."
 
III
Soon after Darwin's return he moved to London for the two most active years of his life, to care for his collections and to write up his
 
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observations. At this moment came the third of the great turning points in his life, which as a mysteriously disguised blessing was brought about through ill health. In London he was entering official duties and public scientific service which would undoubtedly have increased and interfered more and more seriously with his work. We can only count it as one of the most fortunate circumstances in the history of science that Darwin at the age of thirty-three was forced to leave London and to move to Down. Here for forty years he never knew for one day the health of an ordinary man; his life was one long struggle against the strain of sickness. But unrealized by him there was the compensation of a mind undisturbed by the constant interruption of outside affairs, such interruption as killed Huxley and is killing so many fine and ambitious men to-day. When I saw Huxley and Darwin side by side in 1879, the one only fifty-four, the other seventy, the younger man looked by far the more careworn of the two. Huxley, the strong man, broke down mentally at fifty-six; Darwin, the invalid, was vigorous mentally at seventy-two.

Darwin's writings fall into three grand series. In the nine years after he returned from the voyage, or between his twenty-seventh and thirty-sixth years, Darwin wrote the first series, including his pre-evolutionary geological and zoological works, his "Coral Reefs" (1842), his "Zoology and Geology of the Voyage of the Beagle" (1844-1846), his "Journal of Researches," the popular narrative of his voyage (1845). Darwin's ill health thereafter shut him off from geology, although his last volume, "The Earthworm," was in a sense geological.

It is characteristic of the life of every great man that his genius and his own self-analysis instinctively guide him to discover his mental needs.

Until the age of forty-five Darwin in his own opinion had not completed his education, in the sense that education is a broad and exact training. He now proceeded to fill the one gap in his training by devoting the eight years of his life, between thirty-seven and forty-five, to a most laborious research upon the barnacles, or Cirripedia. This gave him the key to the principles of the natural or adaptively branching and divergent arrangement of animals through the laws of descent as set forth in the "Origin," which he certainly could not have secured in any other way. The value he placed on his work on the barnacles is of especial import to-day when systematic work is so lightly esteemed by many biologists, young and old. Darwin subsequently, in the words of Hooker, "recognized three stages in his career as a biologist, the mere collector at Cambridge, the collector and observer on the Beagle, and for some years afterwards, and the trained naturalist after, and only after, the Cirripede work." Long before this, however, at the age of twenty-eight, Darwin had begun his career as a Darwinian. In July, 1837, he began his notes on the transmutation of species, based on purely Baconian principles, on the rigid collection of facts which would bear in any way on the variations of animals and plants under domestication and in nature. Rare as was his reasoning power, his powers of observation were of a still more unique order. He persistently and doggedly followed every clue; he noticed little things which escaped others; he always noted exceptions and at once jotted down facts opposed to his theories. On the voyage the marvelous adaptations of animals and plants had been his greatest puzzle. Fifteen months later, in October, 1838, in reading the work of Malthus, on "Population," there flashed across his mind the three-fold clue of the struggle for existence, of constant variability, and of the selection of variations which happen to be adaptive.

The three memorable features of-Darwin's greatest work, "The Origin of Species," are, that he was twenty-one years in preparing it, that, although by 1844 he was a strongly convinced evolutionist and natural selectionist, he kept on with his observations for fifteen years, and the volume even then would have been still longer postponed but for a wonderful coincidence, which constitutes the third and not the least memorable feature. This coincidence was that Wallace had also become an evolutionist and had also discovered the principle of natural selection through the reading of the same essay of Malthus. It is further remarkable that of all persons Wallace selected Darwin as the one to whom to send his paper. It was then through the persuasion of the great botanist Hooker, who had known Darwin's views for thirteen years that these independent discoveries were published jointly on July 1, 1858. All the finest points of Darwin's personal character were displayed at this time; in fact, the entire Darwin-Wallace history up to and including Wallace's noble and self-depreciatory tribute to Darwin on July 1, of last summer, is one of the brightest chapters in the history of science. Wallace himself pointed out the very important distinction that while the theories contained in the two papers published fifty years ago were nearly identical, Wallace had deliberated only three days after coming across the passage in Malthus, while Darwin had deliberated for fifteen years. He modestly declared that the respective credit should be in the ratio of fifteen years to three days.

Several months past the age of fifty Darwin published his epoch-making work (November, 1859), and despite ill health, between fifty and seventy-three, he produced the nine great volumes which expand and illustrate the views expressed in "The Origin of Species."

A parallel to this remarkable late productiveness is that of Kant, who also put forth his greatest work after fifty. Let those past the five
 
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decades take heart, for it appears that while there are inborn differences between men in this regard, imagination, observation, reasoning and production do not necessarily dim with age. Darwin's mind remained young and plastic to the end; his latest and one of his most characteristic works, "The Formation of Vegetable Mould through the Action of Earth Worms" was published at the age of seventy-two, after forty-four years of observation. It contained another and perhaps the most extreme demonstration of Lyell's principle that vast changes in nature are brought about by the slow operation of infinitesimal causes.

Three of Darwin's succeeding volumes are a filling out of the "Origin." "The Variation of Animals and Plants under Domestication" (2 vols., 1868) presents the entire fabric of the notes begun twenty-one years before on the transmutation of species. "The Descent of Man" (1871) was another logical outcome of the "Origin," yet it was only faintly adumbrated by a single allusion in that work to the fact that the transmutation of species necessarily led to the evolution of man. The "Descent" marks the third of the great dates in the history of thought, as the "Origin" marks the second, because it is the final step in the development of ideas which began with Copernicus in 1543. The world-wide sensation, the mighty storm produced by this bold climax of Darwin's work, is so fresh in the memory of all that a mere allusion suffices. The evolutionary or genetic basis for modern psychology as stated in "The Descent of Man" was given still more concrete form in Darwin's succeeding and most delightful volume "The Expression of the Emotions" (1872).

The knowledge of zoology and anatomy displayed in these four evolutionary volumes came from direct observation, vast and systematic reading and note-taking from the simple materials which Darwin could collect at Down. Always penetrating as these observations are, they are still, in my opinion, surpassed in beauty and ingenuity by his marvelous work on plants, published between 1862 and 1880. Here the principles of coadaptation of plants and insects in cross-and self-fertilization, in climbing plants and insectivorous plants, in forms of flowers, in movements of plants, are all brought forth in support of the theory of natural selection and the operation of unknown laws. Darwin's most precise observations and some of his most brilliant discoveries recorded in these volumes laid the foundations of modern experimental botany.

Of his method Darwin writes:

From my early youth I had the strongest desire to understand or explain whatever I observed, that is, to group facts under some general laws. My mind seems to have become a kind of machine for grinding general laws out of large collections of facts.

The only work which Darwin wrote deductively was his "Coral Reefs." Every other volume came through the inductive-deductive process, that is, through an early assemblage of facts followed by a series of trial hypotheses, each of which was rigidly tested by additional facts. The most central of these trial hypotheses was that of the building up of adaptations through the selection of the single adaptive variation out of the many fortuitous variations, and this Darwin was unable to rigidly test by facts but was obliged to leave for verification or disproof by work after him.

Darwin passed away in the year 1882, at the age of 73. Out of the simple and quiet life at Down he had sent forth the great upheaval and revolution.

 
IV

There is no denying that there is to-day a wide reaction against the central feature of Darwin's thought and this leads us to consider the merits of this reaction, as will be more clearly and fully set forth in the succeeding lectures of this series.

Now on this centenary when we are honoring Darwin, many may ask, exactly what is Darwinism? Failure to know leads some to doubt, others to predict a decline, especially where "the wish is father to the thought." Nothing could be less true than to say that there is the least abatement in the force of the main teaching of this great leader, namely, of the evolutionary law of the universe. The vitality of this idea is shown by its invasion of the physical world. Again, Darwinism is the sum of Darwin's observations on earth structure, on plants, animals and man. This vast body of truth and of interpretation still so far surpasses that brought forward by any other observer of nature, and these facts and interpretations are so far confirmed that they have become the very foundation stones of modern biology and geology. Finally, looking at Darwinism as the sum of his generalizations as to the processes of evolution we again find a vast body of well established laws which are also daily becoming more evident. As to the laws of evolution, there is no single biological principle more absolutely proved by the study of living and extinct things since Darwin's time than the broad law of natural selection: certainly the fittest survive and reproduce their kind, the fittest of every degree, classes, orders, genera, species, individuals and even the fittest organs and fittest separate parts of organs. Darwin still gives us the only explanation which has ever been suggested of hundreds of thousands of adaptations of which neither Buffon's view of direct effect of environment nor Lamarck's view of the inheritance of bodily modifications even approach an explanation worthy to be considered. Take the egg of the murre or guillemot, which is so much larger at one end than the other that it can not roll off the cliff on which it is laid, or the seasonal changes of color in the ptarmigan, every one of which is protective.
 
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There is some lack of perspective, some egotism, much one-sidedness in modern criticism. The very announcement, "Darwin deposed," attracts such attention as would the notice "Mt. Blanc removed"; does it not argue courage to attack a lion even when deceased? Preoccupation in the study of one great law, as in the case of Bateson on Mendelism and De Vries on Mutation blinds to every other law. To be dispassionate, let us remember that Darwin's hypothesis was framed in 1838, seventy years ago. Are the two great Cambridge men, Newton and Darwin, lesser men because astronomy and biology are progressive sciences? Secondly, to know your Darwin you must not judge him by single passages but by all he wrote. Darwin is not to be known through the extremes of those of his followers with whom an hypothesis has become a creed. Heading him afresh and through and through we discover that his "variation" and "variability" are very broad and elastic terms. Every actual example he cites of his main hypothesis, such as the speed of the wolf, or the deer, or the long neck of the giraffe, is a variation both heritable and of adaptive value.

"When we put together all the concrete cases which he gave to illustrate his views of selection we see that he includes both continuous and discontinuous variations, both the shades of difference of kind and proportion and the little leaps or saltations from character to character. For example, certain cases of immunity to disease are now known to be "unit characters" in Bateson's sense, or "mutants" in the De Vries sense. Darwin repeatedly referred to immunity as a variation which would be preserved by selection. Moreover, Darwin's own repeated assertion of his profound ignorance of the laws of variation certainly pointed the way to the investigation of these laws, and it is this very study which is modifying the applications of his selection hypothesis.

From first to last Huxley maintained that it would require many years of study before naturalists could say whether Darwin had been led to overestimate the power of natural selection. Darwin's mind from first to last was also open on this point. Through every edition of the "Origin" we find the passage:

The laws governing the incipient or primordial variations (unimportant except as the groundwork for selection to act on and then all important) 1 shall discuss under several heads. But I can come, as you may well believe, to only very partial and imperfect conclusions.

In 1869 and in the latest edition of the "Origin" Darwin speaks of "individual differences" as of paramount importance, but he illustrates these differences by such instances as the selection of passenger pigeons with more powerful wings, or the selection of the lightest colored birds in deserts.

There can be no question, however, that Darwin did love his selection theory, and somewhat overestimated its importance. His conception of selection in nature may be compared to a series of concentric circles constantly narrowing from the largest groups down to the minutest structures. In the operations of this intimate circle of minute variations within organisms he was inclined to believe two things: first, that the fit or adaptive always arises out of the accidental, or that out of large and minute variations without direction selection brings direction and fitness; second, as a consistent pupil of Lyell, he was inclined to believe that the chief changes in evolution are slow and continuous. The psychology of the former is that he was in a reaction state from the prevailing false teleology. He was not expecting that purposive or teleological or even orthogenetic laws of variation would be discovered. William James has thus recently expressed and endorsed the spirit of Darwinism as a natural philosophy in the follow words:

It is strange, considering how unanimously our ancestors felt the force of this argument [that is, the teleological], to see how little it counts for since the triumph of the Darwinian theory. Darwin opened our minds to the power of the chance-happenings to bring forth "fit" results if only they have time to add themselves together. He showed the enormous waste of nature in producing results that get destroyed because of their unfitness.

The simple question before us to-day and in the succeeding lectures of this course is: is this true? This really involves the deep seated query whether the intimate or minute parts of living things are operating under natural laws like non-living things, or are really lawless.

Before expressing my individual opinion based on my own researches of the last twenty years I may summarize the general modern dissent: in three points it may be said that Darwin's teachings are not accepted to-day.

First, his slowly developed belief in the inheritance of bodily modifications as well as the provisional "assemblage theory" of heredity which he called pangenesis, have been set aside for Weismann's law that heredity lies in the continuity of a specific heredity plasm, and for want of evidence of the transmission of acquired characters.

Second, while his prevailing belief that changes in organisms are in the main slow and continuous is now positively demonstrated to be correct by the study of descent in fossil organisms, there is also positive evidence for the belief which he less strongly entertained that many changes are discontinuous or mutative, as held by Bateson and De Vries.

Finally, his belief that out of fortuitous or undirected variations in minute characters arise direction, purpose and adaptation through selection still lacks proof by either observation or experiment. Fossil
 
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and other descent series entirely unknown in Darwin's time certainly prove beyond question that law rather than chance is prevailing in variation.

What the nature of these laws is it is still too early to say. Personally I am strongly of the opinion that the laws of life, like the ultimate laws of physics, may ultimately prove to be beyond analysis.

To allow myself just one flight of fanciful statement drawn from personal observation and reflection I may say there is a likeness between the unit forces working in a single organism, both as revealed by the microscope and in fossil series, and the individual soldiers composing a giant army. The millions of well-ordered activities in the body correspond with the millions of intelligently trained men who compose the army; the selection process or the survival of the fittest is like the competition between two armies, between the Russian and Japanese, for example. It is an outward and visible competition between two internally prepared and well-ordered hosts of units and groups of units. Selection is continuously working upon the army as a whole and also upon every unit which affects survival—an immunity unit, an intelligence unit, a speed unit, a color or group of color units; just as in the army it is working upon units of courage, of strategy, of precision of fire, of endurance, of mass. In this sense it is perfectly true to say with Darwin "that selection works upon certain single variations." It is not true or at least it is not shown, that these variations are a matter of chance; they rather appear to be a matter of law as indeed Darwin foresaw when he stated that he used the word "chance" merely as a synonym of "ignorance."

In the present state of biology we are studying the behavior of the thousands of parts, sometimes of blending, sometimes of separate, sometimes of paired or triplicate units, which compose the whole and make up the individual organism. Natural selection determines which organism shall win; more than this, it determines which serviceable activities of each organism shall win. Here lie the limits of its power. Selection is not a creative principle, it is a Judicial principle. It is one of Darwin's many triumphs that he positively demonstrated that this judicial principle is one of the great factors of evolution. Then he clearly set our task before us in pointing out that the unknown lies in the laws of variation and a stupendous task it is. At the same time he left us a legacy in his inductive and experimental methods by which we may blaze our trail.

Therefore, in this anniversary year, we do not see any decline in the force of Darwinism but rather a renewed stimulus to progressive search. As Huxley says:

But this one thing is perfectly certain—that is, it is only by pursuing his method, by that wonderful single-mindedness, devotion to truth, readiness to sacrifice all things for the advance of definite knowledge, that we can hope to come any nearer than we are at present to the truths which he struggled to attain.
 
V

On December 8, 1879, when Darwin was in his seventieth year and I in my twenty-second, I had the rare privilege of meeting him and looking steadily in his face during a few moments' conversation. It was in Huxley's laboratory, and I was at the time working upon the anatomy of the Crustacea. The entry in my journal is as follows:

This is a red letter day for me. As I was leaning over my lobster (Homarus vulgaris) this morning, cutting away at the brain, I raised my head and looked up to see Huxley and Darwin passing by me. I believe I never shall see two such great naturalists together again. I went on apparently with skill, really hacking my brain away, and cast an occasional glance at the great old gray-haired man. I was startled, so unexpected was it, by Huxley speaking to me and introducing me to Darwin as "an American who has already done some good paleontological work on the other side of the water." I gave Darwin's hand a tremendous squeeze (for I never shall shake it again) and said, without intending, in an almost reverential tone, "I am very glad to meet you." He stands much taller than Huxley, has a very ruddy face, with benevolent blue ej^es and overhanging eyebrows. His beard is quite long and perfectly white and his hair falls partly over a low forehead. His features are not good. My general impression of his face is very pleasant. He smiled broadly, said something about a hope that Marsh with his students would not be hindered in his work, and Huxley saying, "I must not let you talk too much," hurried him on into the next room.

I may add as distinctly recorded in my memory, that the impression of Darwin's bluish-gray eyes, deepset under the overhanging brows, was that they were the eyes of a man who could survey all nature.

Another memory of interest is that the instant Huxley closed the door I was mobbed as the "lucky American" by the ninety less fortunate students of Great Britain and other countries.

Huxley's solicitude for Darwin's strength was characteristic of him. He often alluded to himself as "Darwin's bull dog."

I have already stated that of the two men Darwin gave the impression of enjoying better health. Huxley was then sixteen years the younger, yet the burdens and strain of London life made him look less young and hale. In this connection an earlier jotting from the same laboratory is as follows:

Huxley comes in as the clock strikes and begins to lecture at once, almost before it ceases. He looks old and somewhat broken, his eyes deeply sunken, but as a lecturer as strong as he ever could have been. His language is very simple too.
 
VI
What of the conflict between science and theology? We are now in a process of readjustment, but let us imagine our descendants in
 
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this university three or four hundred years hence looking back on the history of man. With larger perspective they will see two grand thought movements; the first, oriental, marked by oriental lack of curiosity about natural law, a great moral and spiritual movement developing along the Nile, the Tigris and Euphrates, out of five thousand years of hard human experience, culminating in Judea in the faith that nature is the continuous handiwork of God, in a supreme standard of righteousness, and in the simple expression of the human law "thou shalt love thy neighbor as thyself."

Another movement begins six centuries earlier in the inquiring mind of the west, always characterized by curiosity about nature. It was the search for natural law. Its rapid progress among the Greeks sadly terminates with the fall of Greece. After nineteen centuries it revives with Copernicus and Galileo and culminates in Darwin. Man is a part of nature; in the study of nature man finds intellectual delight; in the laws of nature man finds his physical welfare.

The conflict of opinion aroused by Darwin will subside like the evil passions of our Civil War. Surely the reverent study of nature can not lead man astray. These two great movements of love and of knowledge, first of the spiritual then of the intellectual and physical well-being of man, will be seen to be a harmony and not a discord.

  1. Address delivered at Columbia University on the one hundredth anniversary of Darwin's birth, as the first of a series of nine lectures on "Charles Darwin and His Influence on Science."
  2. Alfred Tennyson, Edgar Allen Poe, Felix Mendelssohn, Oliver Wendell Holmes, William Ewart Gladstone.
  3. "I can not resist forming one on every subject."