Message from the Retiring President of the British Association; The Fifth International Genetics Congress; The American Chemical Society Scientific Notes and News University and Educational Notes Discussion and Correspondence: The "Washboard" or 66 'Corduroy” Effect Due to Travel of Automobiles over Dirt Roads: L. E. DODD. The Reversible Mixing of Substances in the Condensed State at the Absolute Zero of Temperature: PROFESSOR R. D. KLEEMAN. Double Covey of California Valley Quail: PROFESSOR R. M. SELLE Scientific Books: Rignano's Man not a Machine: PROFESSOR G. H. PARKER. de Murtonne's Traité de Geographie Physique: JOHN W. HARSHBERGER Scientific Apparatus and Laboratory Methods: Accurately Timed Intermittent Lighting: DR. DEAN A. PACK. Centrifuging Filterable Viruses: DR. M. S. MARSHALL. Persimmon Seeds for Class Use: PROFESSOR V. H. YOUNG Special Articles: The Occurrence of the Platinum Metals: PROFESSOR JAS. LEWIS HOWE. The Encystment of Paramoecium in the Recta of Frogs; Natural and Experimental Ingestion of Paramoecium by Cockroaches: DR. L. R. CLEVELAND Science News 209 211 214 214 217 218 220 X SCIENCE: A Weekly Journal devoted to the Advancement of Science, edited by J. McKeen Cattell and published every Friday by THE SCIENCE PRESS New York City: Grand Central Terminal. Lancaster, Pa. Garrison, N. Y. Single Copies, 15 Cts. SCIENCE is the official organ of the American Association for the Advancement of Science. Information regarding membership in the Association may be secured from the office of the permanent secretary, in the Smithsonian Institution Building, Washington, D. C. Annual Subscription, $6.00. Entered as second-class matter July 18, 1928, at the Post Office at Lancaster, Pa., under the Act of March 8, 1879. DARWIN'S THEORY OF MAN'S MY LORD MAYOR, MR. VICE-CHANCELLOR, LADIES My first duty as your president, and it is a very pleasant one, is to send the following message in your name to H.R.H. The Prince of Wales: YOUR ROYAL HIGHNESS, The British Association for the Advancement of Science, now assembled in Leeds to begin another session, can not allow your year of office to terminate without offering to you sincere and humble congratulations on the happy results which have attended your presidency. A year ago, in the historic city of Oxford, you did British science the signal honor of coming among us as our president; the meeting you then inaugurated set a standard which future gatherings will strive to emulate. The inspiring message you then addressed to us, and through us to men of science in every part of the empire, has already borne fruit. We are within sight of a closer union, for which the association itself has always striven, between men of science overseas and their colleagues at home, in their endeavor to solve problems of imperial concern. It is too soon as yet to assess the value of the harvest of science planted under your ægis, for the best vintages of science mature slowly, but of this we are certain: the interest Your Royal Highness has taken in the work of this association will prove a permanent source of encouragement for all who work for the betterment of life through increase of knowledge. To-night we proudly add your presidential banner to those of the great men of science who have presided over this association since its inception at York ninety-six years ago. In olden times men kept their calendars by naming each year according to its outstanding event. I have no doubt that in future times the historian of this association, when he comes to distinguish the presidential year which opened so auspiciously in Oxford twelve months ago, will be moved to revert to this ancient custom and name it the Prince's Year. And I am under no misapprehension as to what will happen when our historian comes to the term which I have now the honor of inaugurating at Leeds; he will immediately relapse to the normal system of numerical notation. Nor will our historian fail to note, should he be moved to contrast the meeting at Oxford with 1 The presidential address before the British Association for the Advancement of Science given at Leeds on August 31. that which now begins at Leeds, that some mischievous sprite seems to have tampered with the affairs of this association. For how otherwise could he explain the fortune which fell to ancient Oxford, the home of history? To her lot fell a brilliant discourse on the application of science to the betterment of human lives, while Leeds, a city whose life's blood depends on the successful application of science to industry, had to endure, as best she could, a discourse on a theme of ancient history. For the subject of my address is man's remote history. Fifty-five years have come and gone since Charles Darwin wrote a history of man's descent. How does his work stand the test of time? This is the question I propose to discuss with you to-night in the brief hour at my disposal. In tracing the course of events which led up to our present conception of man's origin, no place could serve as a historical starting-point so well as Leeds. In this city was fired the first verbal shot of that long and bitter strife which ended in the overthrow of those who defended the Biblical account of man's creation and in a victory for Darwin. On September 24, 1858-sixty-nine years ago-the British Association assembled in this city just as we do to-night; Sir Richard Owen, the first anatomist of his age, stood where I now stand. He had prepared a long address, four times the length of the one I propose to read, and surveyed, as he was well qualified to do, the whole realm of science; but only those parts which concern man's origin require our attention now. He cited evidence which suggested a much earlier date for the appearance of man on earth than was sanctioned by Biblical records, but poured scorn on the idea that man was merely a transmuted ape. He declared to the assembled association that the differences between man and ape were so great that it was necessary, in his opinion, to assign mankind to an altogether separate order in the animal kingdom. As this statement fell from the president's lips there was at least one man in the audience whose spirit of opposition was rousedThomas Henry Huxley-Owen's young and rising antagonist. I have picked out Huxley from the audience because it is necessary, for the development of my theme, that we should give him our attention for a moment. We know what Huxley's feelings were towards Owen at the date of the Leeds meeting. Six months before, he had told his sister that "an internecine feud rages between Owen and myself," and on the eve of his departure for Leeds he wrote to Hooker: "The interesting question arises: shall I have a row with the great O. there?" I am glad to say the Leeds meeting passed off amicably, but it settled in Huxley's mind what the "row" was to be about when it came. It was to concern man's rightful position in the scale of living things. Two years later, in 1860, when this association met in Oxford, Owen gave Huxley the opportunity he desired. In the course of a discussion Owen repeated the statement made at Leeds as to man's separate position, claiming that the human brain had certain structural features never seen in the brain of anthropoid apes. Huxley's reply was a brief and emphatic denial with a promise to produce evidence in due coursewhich was faithfully kept. This opening passage at arms between our protagonists was followed two days later by that spectacular fight-the most memorable in the history of our association-in which the Bishop of Oxford, the representative of Owen and of orthodoxy, left his scalp in Huxley's hands. To make his victory decisive and abiding, Huxley published, early in 1863, "The Evidences of Man's Place in Nature,” a book which has a very direct bearing on the subject of my discourse. It settled for all time that man's rightful position is among the primates, and that, as we anatomists weigh evidence, his nearest living kin are the anthropoid apes. My aim is to make clear to you the foundations on which rest our present-day conception of man's origin. The address delivered by my predecessor from this chair at the Leeds meeting of 1858 has given me the opportunity of placing Huxley's fundamental conception of man's nature in a historical setting. I must now turn to another issue which Sir Richard Owen merely touched upon but which is of supreme interest to us now. He spent the summer in London, just as I have done, writing his address for Leeds and keeping an eye on what was happening at scientific meetings. In his case something really interesting happened. Sir Charles Lyell and Sir Joseph Hooker left with the Linnean Society what appeared to be an ordinary roll of manuscript, but what in reality was a parcel charged with high explosives, prepared by two very innocent-looking men-Alfred Russel Wallace and Charles Darwin. As a matter of honesty it must be admitted that these two men were well aware of the deadly nature of its contents, and knew that if an explosion occurred, man himself, the crown of creation, could not escape its destructive effects. Owen examined the contents of the parcel and came to the conclusion that they were not dangerous; at least, he manifested no sign of alarm in his presidential address. He dismissed both Wallace and Darwin, particularly Darwin, in the briefest of paragraphs, at the same time citing passages from his own work to prove that the conception of natural selection as an evolutionary force was one which he had already recognized. As I address these words to you I can not help marvelling over the difference between our outlook to-day and that of the audience which Sir Richard Owen had to face in this city sixty-nine years ago. The vast assemblage which confronted him was convinced, al separ cert most without a dissentient, that man had appeared on earth by a special act of creation; whereas the audience which I have now the honor of addressing, and that larger congregation which the wonders of wireless bring within the reach of my voice, if not convinced Darwinists are yet prepared to believe, when full proofs are forthcoming, that man began his career as a humble primate animal, and has reached his present estate by the action and reaction of biological forces ng pass which have been and are ever at work within his body and brain. of an mpha due wed st and f To listel manes the ing This transformation of outlook on man's origin is one of the marvels of the nineteenth century, and to see how it was effected we must turn our attention for a little while to the village of Down in the Kentish uplands and note what Charles Darwin was doing on the very day that Sir Richard Owen was delivering his address here in Leeds. He sat in his study struggling with the first chapter of a new book; but no one foresaw, Owen least of all, that the publication of the completed book, The Origin of Species, fifteen months later (1859), was to effect a sweeping revolution in our way of looking at living things and to initiate a new period in human thought-the Darwinian period-in which we still are. Without knowing it, Darwin was a consummate general. He did not launch his first campaign until he had spent twentytwo years in stocking his arsenal with ample stores of tested and assorted fact. Having won territory with The Origin of Species, he immediately set to work to consolidate his gains by the publication in 1868 of another book, The Variation of Animals and Plants under Domestication—a great and valuable treasury of biological observation. Having thus established an advanced base, he moved forwards on his final objective the problem of human beginnings-by the publication of The Descent of Man (1871), and that citadel capitulated to him. To make victory doubly certain he issued in the following year-1872-The Expression of the Emotions in Man and Animals. Many a soldier of truth had attempted this citadel before Darwin's day, but they failed because they had neither his generalship nor his artillery. Will Darwin's victory endure for all time? Before attempting to answer this question, let us look at what kind of book The Descent of Man is. It is a book of history-the history of man, written in a new way -the way discovered by Charles Darwin. Permit me to illustrate the Darwinian way of writing history. If a history of the modern bicycle had to be written in the orthodox way, then we should search dated records until every stage was found which linked the two-wheeled hobby-horse, bestrode by tall-hatted fashionable men at the beginning of the nineteenth century, to the modern "jeopardy" which now flashes past us in country lanes. But suppose there were no dated records only a jumble of antiquated machines stored in the cellar of a museum. We should, in this case, have to adopt Darwin's way of writing history. By an exact and systematic comparison of one machine with another we could infer the relationship of one to another and tell the order of their appearance, but as to the date at which each type appeared and the length of time it remained in fashion, we could say very little. It was by adopting this circumstantial method that Darwin succeeded in writing the history of man. He gathered historical documents from the body and behavior of man and compared them with observations made on the body and behavior of every animal which showed the least resemblance to man. He studied all that was known in his day of man's embryological history and noted resemblances and differences in the corresponding histories of other animals. He took into consideration the manner in which the living tissues of man react to disease, to drugs and to environment; he had to account for the existence of diverse races of mankind. By a logical analysis of his facts Darwin reconstructed and wrote a history of man. Fifty-six years have come and gone since that history was written; an enormous body of new evidence has poured in upon us. We are now able to fill in many pages which Darwin had perforce to leave blank, and we have found it necessary to alter details in his narrative, but the fundamentals of Darwin's outline of man's history remain unshaken. Nay, so strong has his position become that I am convinced that it never can be shaken. Why do I say so confidently that Darwin's position has become impregnable? It is because of what has happened since his death in 1882. Since then we have succeeded in tracing man by means of his fossil remains and by his stone implements backwards in time to the very beginning of that period of the earth's history to which the name Pleistocene is given. We thus reach a point in history which is distant from us at least 200,000 years, perhaps three times that amount. Nay, we have gone farther, and traced him into the older and longer period which preceded the Pleistocene-the Pliocene. It was in strata laid down by a stream in Java during the latter part of the Pliocene period that Dr. Eugene Dubois found, ten years after Darwin's death, the fossil remains of that remarkable representative of primitive humanity to which he gave the name Pithecanthropus, or ape-man; from Pliocene deposits of East Anglia Mr. Reid Moir has recovered rude stone implements. If Darwin was right, then as we trace man backwards in the scale of time he should become more bestial in form-nearer to the ape. That is what we have found. But if we regard Pithecanthropus with his small and simple yet human brain as a fair representative of the men of the Pliocene period, then evolution must have proceeded at an unexpectedly rapid rate to culminate to-day in the higher races of mankind. The evidence of man's evolution from an ape-like being, obtained from a study of fossil remains, is definite and irrefutable, but the process has been infinitely more complex than was suspected in Darwin's time. Our older and discarded conception of man's transformation was depicted in that well-known diagram which showed a single file of skeletons, the gibbon at one end and man at the other. In our original simplicity we expected, as we traced man backwards in time, that we should encounter a graded series of fossil forms-a series which would carry him in a straight line towards an anthropoid ancestor. We should never have made this initial mistake if we had remembered that the guide to the world of the past is the world of the present. In our time man is represented not by one but by many and diverse racesblack, brown, yellow and white; some of these are rapidly expanding, others are as rapidly disappearing. Our searches have shown that in remote times the world was peopled, sparsely it is true, with races showing even a greater diversity than those of to-day, and that already the same process of replacement was at work. To unravel man's pedigree, we have to thread our way, not along the links of a chain, but through the meshes of a complicated network. We made another mistake. Seeing that in our search for man's ancestry we expected to reach an age when the beings we should have to deal with would be simian rather than human, we ought to have marked the conditions which prevail amongst living anthropoid apes. We ought to have been prepared to find, as we approached a distant point in the geological horizon, that the forms encountered would be as widely different as are the gorilla, chimpanzee and orang, and confined, as these great anthropoids now are, to limited parts of the earth's surface. That is what we are now realizing; as we go backwards in time we discover that mankind becomes broken up, not into separate races as in the world of to-day, but into numerous and separate species. When we go into a still more remote past they become so unlike that we have to regard them not as belonging to separate species but different genera. It is amongst this welter of extinct fossil forms which strew the ancient world that we have to trace the zigzag line of man's descent. Do you wonder we sometimes falter and follow false clues? We committed a still further blunder when we set out on the search for man's ancestry: indeed, some of us are still making it. We expected that man's evolution would pursue not only an orderly file of stages, but that every part of his body-skull, brain, jaws, teeth, skin, body, arms and legs-would at each stage become a little less ape-like, a little more man-like. Our searches have shown us that man's evolution has not proceeded in this orderly manner. In some extinct races, while one part of the body has moved forwards another part has lagged behind. Let me illustrate this point because it is important. We now know that, as Darwin sat in his study at Down, there lay hidden at Piltdown, in Sussex, not thirty miles distant from him, sealed up in a bed of gravel, a fossil human skull and jaw. In 1912, thirty years after Darwin's death, Mr. Charles Dawson discovered this skull and my friend Sir Arthur Smith Woodward described it, and rightly recognized that skull and jaw were parts of the same individual, and that this individual had lived, as was determined by geological and other evidence, in the opening phase of the Pleistocene period. We may confidently presume that this individual was representative of the people who inhabited England at this remote date. The skull, although deeply mineralized and thick-walled, might well have been the rude forerunner of a modern skull, but the lower jaw was so ape-like that some experts denied that it went with the human fossil skull at all, and supposed it to be the lower jaw of some extinct kind of chimpanzee. This mistake would never have been made if those concerned had studied the comparative anatomy of anthropoid apes. Such a study would have prepared them to meet with the discordances of evolution. The same irregularity in the progression of parts is evident in the anatomy of Pithecanthropus, the oldest and most primitive form of humanity so far discovered. The thigh-bone might easily be that of modern man, the skull-cap that of an ape, but the brain within that cap, as we now know, had passed well beyond an anthropoid status. If merely a lower jaw had been found at Piltdown an ancient Englishman would have been wrongly labelled "Higher anthropoid ape"; if only the thigh-bone of Pithecanthropus had come to light in Java, then an ancient Javanese, almost deserving the title of anthropoid, would have passed muster as a man. Such examples illustrate the difficulties and dangers which beset the task of unravelling man's ancestry. There are other difficulties; there still remain great blanks in the geological record of man's evolution. As our search proceeds these blanks will be filled in, but in the meantime let us note their nature and their extent. By the discovery of fossil remains we have followed man backwards to the close of the Pliocene-a period which endured at least for a quarter of a million years, but we have not yet succeeded in tracing him through this period. It is true that we have found fossil teeth in Pliocene deposits which may be those of bran at e Ore erol SOM redir llus at f an ape-like man or of a man-like ape; until we find other parts of their bodies we can not decide. When we pass into the still older Miocene period-one which was certainly twice as long as the Pliocene-we are in the heyday of anthropoid history. Thanks to the labors of Dr. Guy E. Pilgrim, of the Indian Geological Survey, we know already of a dozen different kinds of great anthropoids which lived in Himalayan jungles during middle and later Miocene times; we know of at least three other kinds of great anthropoids which lived in the contemporary jungles of Europe. Unfortunately we have found as yet only the most resistant parts of their bodies-teeth and fragments of jaw. Do some of these fragments represent a human ancestor? We can not decide until a lucky chance brings to light a limb-bone or a piece of skull, but no one can compare the teeth of these Miocene anthropoids with those of primitive man, as has been done so thoroughly by Professor William K. Gregory, and the conviction that in the dentitions of the exand s tinct anthropoids of the Miocene jungles we have the ancestral forms of human teeth. s de of the red T escape It is useless to go to strata still older than the Miocene in search of man's emergence; in such strata we have found only fossil traces of emerging anthropoids. All the evidence now at our disposal supports the conclusion that man has arisen, as Lamarck and Darwin suspected, from an anthropoid ape not higher in the zoological scale than a chimpanzee, and that the date at which human and anthropoid lines of descent began to diverge lies near the beginning of the Miocene period. On our modest scale of reckoning, that gives man the respectable antiquity of about one million years. Our geological search, which I have summarized all too briefly, has not produced so far the final and conclusive evidence of man's anthropoid origin; we have not found as yet the human imago emerging from its anthropoid encasement. Why, then, do modern anthropologists share the conviction that there has been an anthropoid stage in our ancestry? They are no more blind than you are to the degree of difference which separates man and ape in structure, in appearance and in behavior. I must touch on the sources of this conviction only in a passing manner. Early in the present century Professor G. H. F. Nuttall, of Cambridge University, discovered a trustworthy and exact method of determining the affinity of one species of animal to another by comparing the reactions of their blood. He found that the blood of man and that of the great anthropoid apes gave almost the same reaction. Bacteriologists find that the living anthropoid body possesses almost the same susceptibilities to infections, and manifests the same reactions, as does the body of man. So alike are the brains of man and anthropoid in their structural organization that surgeons and physiologists transfer experimental observations from the one to the other. When the human embryo establishes itself in the womb it throws out structures of a most complex nature to effect a connection with the maternal body. We now know that exactly the same elaborate processes occur in the anthropoid womb and in no other. We find the same vestigial structures--the same "evolutionary postmarks"-in the bodies of man and anthropoid. The anthropoid mother fondles, nurses and suckles her young in the human manner. This is but a tithe of the striking and intimate points in which man resembles the anthropoid ape. In what other way can such a myriad of coincidences be explained except by presuming a common ancestry for both? The crucial chapters in Darwin's Descent of Man are those in which he seeks to give a historical account of the rise of man's brain and of the varied functions which that organ subserves. How do these chapters stand to-day? Darwin was not a professional anatomist and therefore accepted Huxley's statement that there was no structure in the human brain that was not already present in that of the anthropoid. In Huxley's opinion the human brain was but a richly annotated edition of the simpler and older anthropoid book, and this edition, in turn, was but the expanded issue of the still older original primate publication. Since this statement was made thousands of anatomists and physiologists have studied and compared the brain of man and ape; only a few months ago Professor G. Elliot Smith summarized the result of this intensive enquiry as follows: "No structure found in the brain of an ape is lacking in the human brain, and, on the other hand, the human brain reveals no formation of any sort that is not present in the brain of the gorilla or chimpanzee. The only distinctive feature of the human brain is a quantitative one." The difference is only quantitative but its importance can not be exaggerated. In the anthropoid brain are to be recognized all those parts which have become so enormous in the human brain. It is the expansion of just those parts which have given man his powers of feeling, understanding, acting, speaking and learning. Darwin himself approached this problem not as an anatomist but as a psychologist, and after many years of painstaking and exact observation, succeeded in convincing himself that, immeasurable as are the differences between the mentality of man and ape, they are of degree, not of kind. Prolonged researches made by modern psychologists have but verified and extended Darwin's conclusions. No matter what line of evidence we select to follow-evidence gathered by anatomists, by embryologists, by physiologists or by |