摘要:

THE ages of the Jewi partriarchs as recorded have provoked much discussion andjrsp'eculation. Has the span of life decreased during the passage of the centuries? Census statistics show, at any rate in Great Britain, that the expectation of life at birth has increased considerably in recent years. This, however, does not necessarily mean increased longevity, and investigations on remains of men of periods about two thousand years ago suggest that the expectation of life in advanced ages has actually decreased. The men who survived in those days were necessarily of strong constitutions. To those who may have hoped that science will soon provide the means whereby the span of human life may be prolonged, the critical consideration of the factors concerned in the onset of old age given by Sir Humphry Rolleston in the following pages will show that such hope is as yet vain. This does not necessarily imply, however, that the declining years of life cannot, in certain cases, be rendered less irksome.As is well known, certain primitive organisms, such as Paramcecium, may be described as immortal. Why then are multicellular animals mortal? The mutual influence of the cells of the body upon one another appears to be the basis both for the rise of the multicellular animals in the scale of life and also for their mortality. In artificial cultures certain of the cells of the higher organisms can live and multiply indefinitely, provided that they are supplied with suitable nutriment and their waste products removed. But if the latter accumulate to any extent they exert an inhibitory action on the life and reproductive power of the cells: it appears possible, then, that some similar process may account for the gradual decay of the body's cells in old age. On the other hand, one of the most important, if not the dominant factor, in determining the span of life, is inheritance, and this is acted on by the other factors, the sum of which forms the environment in its broadest sense. A favourable environment is produced by healthy living, especially the avoidance of excesses of every kind: and in such a case a very fair degree of mental and physical vigour may be retained even to the last. But few people escape lesions, produced by some kind of infection during the course of their life and tending to shorten it. Are there any means by which the span of life may be prolonged or old age rendered less irksome, by which, in fact, the body may be ' rejuvenated '?On the hypothesis that old age is largely caused by the decay of those cells in the sexual glands which are responsible for the onset of puberty and the development of the secondary sex characters of the individual, Steinach and Voronoff have devised operations to increase the activity of these cells and thus postpone the onset of old age. They have claimed that, by stimulating the individual's own cells to increased activity or by supplying the necessary secretions from foreign cells introduced into the body by grafting, they have been enabled to prolong life and postpone senility in both animals and men. In so far as the symptoms of old age are due to the decrease in the secretions of these glands, it should be possible to relieve them by increasing the supply of these secretions, but to assume that the decrease in the latter plays the sole, or even the major part in the onset of old age, appears to be to take too narrow a view, considering the mutual influence which the cells of the body are known to exert upon one another. There appears, then, to be no short cut to the abolition of old age and the prolongation of life. Each of us must watch his (or her) step from the day we are born. As Sir Humphry Rolleston expresses it: for a long life there are necessary " a judicious choice of parents, avoidance of disease and worry, moderation in all things, mental and physical exercise, jin open-air life, serenity and charity to all men." The prescription seems simple, but the present and coming generations may find it increasingly difficult to carry out under the stress of life under modern conditions.

ISSN:0028-0836    

DOI:10.1038/120001a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MY year of office as president of the British Association has come to an end, and I cant only express my regret to the members of the Association, and to our hosts the City and Univer sity of Leeds, that I am unable to attend personally in order to take my leave. At Oxford last year I ventured in my ad4ress to lay before the meeting a view of the relations between science and the State. I felt subsequently some justification for having chosen this topic, when I observed in the proceedings of tIie Imperial and Colonial Conferences of the past year the extraordinary emphasis laid upon the value of scientific research in relation to imperial develop ment. Both conferences set up special committees on research, and we cannot but believe and rejoice that the foundations of an imperial scientific service are being firmly laid. The Prime Minister of Australia indicated“the application of science both to our primary and secondary industries”as“the most important thing for Empire trade”; more recently our ex-president, the Earl of Balfour, invited the attention of the House of Lords to“the enormous value of the work given by men of science, with the most lavish generosity,”to the study of problems of the common welfare. Such events as these place it beyond doubt that one of the main objects of the British Association itself is in process of achievement, namely, that of“obtaining more general attention for the objects of science.”The Association, the so-called parlia ment of science, is one of the chief instruments to that end, and I trust that the public support will continue, in increasing measure, to be accorded to its work. Its powers, I am happy to say, have been very materially strengthened, during my own term of office, through the splendid generosity of Sir Alfred Yarrow, in making a gift of10,000 for the general purposes of the Association, to be expended, in accordance with his wise provision, in the course of twenty years. I gladly take this opportunity of publicly repeating the thanks of the Association to Sir Alfred Yarrow. In resigning the chair to Sir Arthur Keith, I can whole-heartedly congratulate. the Association on its choice of my successor. His name stands very high in the science of man’s origin and early bio logical history. I have reason to believe that when any one in this country digs up a bone his first instinct (subject to the intervention of the police) is to send it to Sir Arthur Keith. You are to hear from him an address on Darwinism as it stands to-day subject of perennial interest, and more than once one of warm controversy at our own meetings. The occasion of the presidential address does not (I am thankful to say) lend itself to con troversy, but the warmth I am sure you will supply in your welcome to Sir Arthur Keith, and, meeting as you are in Leeds, that warmth will be increased by the traditional quality of Yorkshire hospitality. Read at the inaugural meeting of the Associatioh in Leeds on Wednesday evening,

ISSN:0028-0836    

DOI:10.1038/120013a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MY first duty as yo and it is a very J.NJ pleasant one).iito send the following message in your name The Prince of Wales: YOUR ROYAL HIGHNESS. The British Association for the Advancement of Science, now assembled in Leeds to begin another session, cannot allow your year of office to terminate without offering to you sincere and humble con gratulations on the happy results which have attended your presidency. A year ago, in the historic city of Oxford, you did British science the signal honour 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 endeavour to solve problems of Imperial concern. It is too soon as yet to assess the value of the harvest of science planted under your tegis, 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 presi dential banner to those of the great men of science who have presided over this Association since its inception at York ninety-six years ago.SUBJECT OF ADDRESS. 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 mis apprehension as to what will happen when our historian comes to the term which I have now the honour of inaugurating at Leeds; he will immedi ately 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 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 better ment of human lives; while Leeds, a citywhose life’s blood depends on the successful application of science to industry, had to endure, as best she could, a discourse on the 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 in the brief hour at my disposal. THE OPENING SHOT IN THE DARWINIAN BATTLE.Tn 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; 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 lie 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 roused—Thomas Henry Huxley—Owen’s young and rising antagonist. OWEN AND HTJXLEY.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 0. 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. MAN’S POSITION IN THE ANIMAL KINGDOM. Two years later, in 1860, when the British Association met in xford, Owen gave Huxley the opportunity he desired In the course of a discus sion 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 course—which was faithfully kept. This opening passage at arms between our pro tagonists 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 ortho doxy, 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. OWEN’S OPINIoN OF DARWINISM. My aim is to make clear 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 his torical 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 ad mitted 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 recognised.THE TRANSFORMATION OF OUR OUTLOOK ON MAN’S ORIGIN. As I address these words to you I cannot 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-nii years ago. The vast assemblage which confronted him, wa convinced, almost without a dissentient, that man had appeared on earth by a special act of creation; whereas the audessing, 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 which have been and are ever at work within his body and brain.DARWIN’S GENERALSHIP. 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 atten tion 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 diving 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 twenty-two years in stocking his arsenal with ample stores of tested and assorted fact. Having won territory with“The Origin of Species,”be 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 valu able treasury of biological observation. Having thus established an advanced base, he moved for wards 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—187-2—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. HISTORY AS WRITTEN BY DARWIN,Will Darwin’s victory endure for all time? Be fore 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 re lationship of one to another and tell the Qrder 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 behaviour of man and compared them with obser vations made on the body and behaviour 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. DARWIN’S POSITION HAS BECOME IMPREGNABLE. 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. TUE EVIDENCE OF FOSSIL REMAINS.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 an4 by his stone imple ments 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 re markable 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 back wards in the scale of tim.e 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 unex pectedly rapid rate to culminate to-day in the higher races of mankind. MAN’S DESCENT HAS NOT BEEN IN A STRAIGHT LINE, 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 infiuiitely more complex than was suspected in Darwin’s time. Our older and discarded concep tion of man’s transformation was depicted in that well-known diagram which showed a sing’e 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 races—black, 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. THE DIVERSITY OF FORM IN ANCIENT TIMES.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 en countered 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 realising; 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. Do you wonder we sometimes falter and follow false clues? DISCORDANT EVOLUTION.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 iorwards another part has lagged behind. Let e illustrate this point because it is important. We now know that, as Darwin sat in his study at I)own, 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. Tn 1912, thirty years after Darwin’s death, Mr. Charles Dawson discovered this skull and my friend Sir Arthur Smith Wood- ward described it, and rightly recognised 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 mineralised and thick-walled, might well have been the rude fore runner 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 progres sion of parts is evident in the anatomy of Pithecan thropus, 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 Putdown, an ancient Englishman would have been wrongly labelled‘Higher anthropoid ape’; if only the thigh-bone of Pithecanthropus had come to light j Java, then an ancient Javanese, almost deserving the title of anthropoid, would have passed muster as a man. BLANKS STILL REMAIN IN THE GEOLOGICAL RECORD.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. Tt is true that we have found fossil teeth in Pliocene deposits which may be those of an ape like man or of a man-like ape; until we find other parts of their bodies we cannot 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 labours of Dr. Guy E. Pilgrim, of the Indian Geological Survey, we know already 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 cannot 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 Dr. William K. Gregory, and escape the conviction that in the dentitions of the extinct anthropoids of the Miocene jungles we have the ancestral forms of human teeth. DATE OF MAN’S EMERGENCE. 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 chim panzee, 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. PROOFS OF OUR ANTmaoPorn ANCESTRY.Our geological search, which I have summarised 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 behaviour. I must touch on the sources of this conviction only in a passing manner. Early in the present century, Prof. G H. P. Nuttall, of the University of Cam bridge, 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 sus ceptibilities 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 organisation 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 connexion with the maternal body. We now know that exactly the same elab orate processes occur in the anthropoid womb and in no other. We find the samp vestigial structures—the same‘evolutionary post-marks‘—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 EVOLUTION OF MAN’S BRAIN. 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 tl 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 that 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; oniy a few months ago, Prof. G. Elliot Smith summarised the result of this intensive inquiry as follows: C 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 dis tinctive feature of the human brain is a quantitative one.”The difference is only quantitative but its importance cannot be exaggerated. In the anthro poid brain are to be recognised all those parts which have become s. It is the expansion of just those parts which have given man his powers of feeling, understanding, acting, speaking, and learning. THE EVIDENCE OF PSYCHOLOGY.Darwin himself approached this problem not as an anatomist but as a psychologist, and after many years of painstaking and exact observation, suc ceeded 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 psychologists——we reach the conviction that man’s brain has been evolved from that of an anthropoid ape and that in the process no new structure has been introduced and no new or strange faculty interpolated. UNEXPLAINED PROBLEMS.In these days our knowledge of the elaborate architecture and delicate machinery of the human brain makes rapid progress, but I should mislead if I suggested that finality is in sight. Far from it; our inquiries are but begun. There is so much we do not yet understand. Will the day ever come when we can explain why the brain of man has made such great progress while that of his cousin the gorilla has fallen so far behind? Can we explain why inherited ability falls to one family and not to another, or why, in the matter of cerebral endow ment, one race of mankind has fared so much bette:r than another? We have as yet no explanation to offer, but an observation made twenty years ago by one on whom Nature has showered great gifts—a former president of this Association and the doyen of British zoologi E. Ray Lankester—deserves quotation in this connexion:“The leading feature in the development and separation of Man from other animals is undoubtedly the relative enormous size of the brain in Man and the corre sponding increase in its activities and capacity. It is a striking fact that it was not in the ancestors of Man alone that this increase in the size of the brain took place at this same period—the Miocene. Other great mammals of the early Tertiary period were in the same case.”When primates made their first appearance in geological records, they were, one and all, small-brained. We have to recognise that the tendency to increase of brain, which culminated in the production of the human organ, was not con fined to man‘s ancestry but appeared in diverse branches of the mammalian stock at a corresponding period of the earth’s history. DARWIN’S CONCEPTION OF EVOLUTION ILLUSTRATED. I have spoken of Darwin as a historian. To describe events and to give the order of their occurrence is the easier part of a historian’s task; his real difficulties begin when he seeks to interpret the happenings of history, to detect the causes which produced them, and explain why one event follows as a direct sequel to another. Up to this point, we have been considering only the materials for man’s history, and placing them, so far as our scanty information allows, in the order of their sequence, but now we have to seek out the biological processes and controlling influences which have shaped the evolutionary histories of man and ape. The evolution of new types of man or of ape is one thing, and the evolution of new types of motor-cars is another, yet for the purposes of clear thinking it will repay us to use the one example to illustrate the other. In the evolution of motor vehicles Darwin’s law of selection has prevailed; there has been severe competition and the types which have answered best to the needs and tastes of the public have survived. The public has selected on two grounds—first for utility, thus illustrating Darwin’s law of natural selection, and secondly because of appearance’s sake; for, as most people know, a new car has to satisfy not only the utilitarian demands of its prospective master but also the sthetic tastes of its prospective mistress, therein illustrating Darwin’s second law—the law of sexual selection. That selection, both utilitarian and a is producing an effect on modern races of mankind and in surviving kinds of ape, as Darwin supposed, cannot well be questioned. in recent centuries the inter-racial competition amongst men for the arable lands of the world is keener than in any known period of human history. THE PRODUCTION OF NEW TYPES.The public has selected its favoured types of car, but it has had no direct hand in designing and producing modifications and improvements which have appeared year after year. To understand how such modifications are produced the inquirer must enter a factory and not only watch artisans shaping and fitting parts together but also visit the designer’s office. In this way an inquirer will obtain a glimpse of the machinery concerned in the evolution of motor-cars. If we are to understand the machinery which underlies the evolution of man and of ape, we have to enter the‘factories where they are pro duced—look within the womb and see the ovum being transferred into an embryo, the embryo into a fcetus, and the fo into a babe. After birth we may note infancy passing into childhood, childhood into adolescence, adolescence into maturity, and maturity into old age. Merely to register the stages of change is not enough; to understand the con trolling machinery we have to search out and uncover the processes which are at work within developing and growing things and the influences which co-ordinate and control all the processes of development and of growth. When we have dis covered the machinery of development and of growth we shall also know the machinery of evolution, for they are the same. MACHINE AND ANIMAL EvOLUTION CONTRASTED.If the simile I have used would sound strange in Darwin’s ear, could he hear it, the underlying meaning would be familiar to him. Over and over again he declared that he did not know how‘variations’were produced, favourable or other wise; nor could he have known, for in his time hormones were undreamt of and experimental embryology scarcely born. With these recent dis coveries, new vistas opened up for students of evolution. The moment we begin to work out the simile I have used and compare the evolutionary machinery in a motor factory with that which regulates the development of an embryo within the w realise how different the two processes are. Let us imagine for a moment what changes would be necessary were we to introduce‘embryological processes’into a car factory. We have to conceive a workshop teeming with clustering swarms of microscopic artisans, mere specks of living matter. In one end of this factory we find swarms busy with cylinders, and as we pass along we note every part of a car in process of manufacture, each part being the business of a particular brigade of micro scopic workmen. There is no apprenticeship in this factory: every employee is born, just as a hive-bee is, with his skill already fully developed. No plans or patterns are supplied; every workman has the needed design in his head from birth. There is neither manager, overseer, nor foreman to direct and co-ordinate the activities of the vast artisan armies. And yet if parts are to fit when assembled, if pinions are to mesh and engines run smoothly, there must be some method of co-ordination. It has to be a method plastic enough to permit diffi culties to be overcome when such are encountered and to permit the introduction of advantageous modifications when these are needed A modern works manager would be hard put to were he asked to devise an automatic system of control for such a factory, yet it is just such a system that we are now obtaining glimpses of in the living workshops of Nature.THE MACHINERY OF DEVELOPMENT. I have employed a crude simile to give the lay mind an inkling of what happens in that‘factory’where the most complicated of machines are forged—the human body and brain. The fertilised ovum divides and redivides; one brood of microscopic living units succeeds another, and as each is pro duced the units group themselves to form the‘parts’of an embryo. Each‘part’is a liongeries of inter dependent societies. How are their respective needs regulated, their freedoms protected, and their mano timed l Experimental embiyologists have begun to explore and discover the machinery of regulation. We know enough to realise that it will take many generations of investigators to work over the great and new field which is thus opening up. When this is done we shall be in a better position to discuss the cause of‘variation‘and the machinery of evolution. THE MACHINERY OF GROWTH.If we know only a little concerning the system of government which prevails in the developing em bryo, we can claim that the system which prevails in the growing body, as it passes from infancy to maturity, is becoming better known to us every year. The influence of the sex glands on the growth of the body has been known since ancient times; their removal in youth leads to a transformation in the growth of every part of the body, altering at the same time the reactions and temperament of the brain. In more recent years medical men have observed that characteristic alterations in the appearance and constitution of the human body can be produced by the action of other glands—the pituitary, thyroid, parathyroid, and adrenals. Under the disorderly action of one or other of these glands individuals may, in the course of a few years, take on so changed an appearance that the differences between them and theirfellows become as great as, or even greater than, those which separate one race of mankind fi another. The physical characters which are thus altered are just those which mark one race off from another. How such effects are produced we did not know until 1904, when the late Prof. E. H. Starling, a leader amongst the great physiologists of our time, laid bare an ancient and fundamental law in the living animal body—his law of hormones. I have pictured the body of a growing child as an immense society made up of myriads of microscopic living units, ever in creasing in numbers. One of the ways—probably the oldest and most important way—-in which the activities of thO communities of the body are co ordinated and regulated is by the postal system discovered by Starling, wherein the missives are hormones—chemical substances in ultra-micro scopic amounts, despatched from one community to another in the circulating blood. Clearly the discovery of this ancient and intricate system opens up fresh vistas to the student of man’s evolution. How Darwin would have welcomed this discovery! It would have given him a rational explanation to so many of his unsolved puzzles, including that of‘correlated variations.’Nor can I in this con nexion forbear to mention the name of one who presided so ably over the affairs of this Association fifteen years ago—Sir E. Sharpey-Schafer. He was the pioneer who opened up this field of in vestigation and has done mOre than anyone to place our knowledge of the nature and action of the glands of internal secretion on a precise basis of experimental observation. With such sources of knowledge being ever extended, and others of great importance, such as the study of heredity, which have been left unmentioned, we are justified in the hOpe that man will be able in due time not only to write his own history but also to explain how and why events took the course they did. In a brief hour I have attempted to answer a question of momentous importance to all of us—What is man’s origin? Was Darwin right when he said that man, under the action of biological forces which can be observed and measured, has been raised from a place amongst anthropoid apes to that which he now occupies? The answer is Yes! and in returning this verdict I speak but as foreman of the jury—a jury which has been empanelled from men who have devoted a life time to weighing the evidence. To the best of my ability I have avoided, in laying before you the evidence on which our verdict was found, the role of special pleader, being content to follow Darwin’s own example—Let the truth speak for itself. 1 Presidential address delivered to the British Association at

ISSN:0028-0836    

DOI:10.1038/120014a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

PROF. ABERG?S valuable analysis of Saxon style does not profess to be in any sense a complete survey of Anglo-Saxon art. It is an attempt to work out a chronology on the basis of the archological (typological) evidence, testing it, however, when possible, by the known facts of history. In any such analysis, Kent, as any one acquainted with the material is bound to realise, takes a prominent place. Prof. Aberg is of the opinion, however, that the undoubtedly distinctive position taken by Kentish culture is not to be attributed so much to race as might be thought if Bede?s statement that the invaders of Kent, the Isle of Wight, and parts of Hampshire, were Jutes, were accepted as indicating some real racial distinction. He is rather of the opinion that social conditions favoured a greater unity there which led to a great commercial expansion. This would have admitted of continental influence in the latter part of the sixth century under Ethelbert, when there was a quickening of Germanic culture in central Europe after the irruptions of the Lombards into Italy and their penetration to the Mediterranean. It is at any rate significant that it is only after the first century succeeding the invasion of Britain that the differentiation of Kent from the rest of England and its marked superiority in artistic effort became apparent. Prof. Aberg?s proofs for this and the subsequent chronology, both for Kent and the rest of England, are worked out in great detail in relation to continental evidence. The case is well argued, though perhaps open to question on points of detail. The isolation of Sussex, for example, surely requires the intervention of no racial or social factor, but is explicable on purely geographical lines.

ISSN:0028-0836    

DOI:10.1038/120029b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ONLY two ycakve elapsed since the publication of Prof. EJit Smith s collection of essays on the evolutio1of man, yet in that brief period much fresh information has accumulated and much discussion of the evidence has taken place. Although in main outline the book remains unchanged, a certain amount of matter, notably that dealing with the cultural evidence, has been excised. The Taungs ape and the Piltdown skull in particular are discussed at some length, in the case of the latter especially with reference to the reconstruction of the brain case, a matter of special importance in view of the supposed discrepancy between the jaw and the rest of the skull. The London skull found on the site of Lloyd s building is made the occasion for a suggestive discussion of the occurrence of left- handedness in man and the ape in the light of the evidence afforded by the asymmetry of the brain.

ISSN:0028-0836    

DOI:10.1038/120030b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

By Cheyenne Campfires is a collection of the oral tradition of the Cheyenne Indians, which Mr. Grinnell himself has arranged in various categories war stories, stories of mystery, hero myths, culture hero stories, and so on. Although their nature is to some extent indicated by this classification, the stories have a closer hold on reality than is usual in most mythological or traditional lore. In many cases the legends are historical and relate to real persons and actual events which took place at the beginning of the last century. Even the earliest stories, which relate to the times long before the Cheyenne reached the Missouri or passed on to the Black Hills, and depict culture elements of which the origin is now forgotten, have this effect of realism. The Cheyenne represent an amalgamation of two tribes or peoples and consequently have two culture heroes. The sacred objects of the tribe are also double they have both the medicine arrows and the buffalo hat. This volume is in a sense an appendix to an earlier book on the Cheyenne by the same author; but although a knowledge of that work is an advantage for the full understanding of this one, the stories carry their own atmosphere and are adequately supple- mented where necessary by the author s comments and explanatory notes.

ISSN:0028-0836    

DOI:10.1038/120031b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

PATRICk GEDDES is a figure apart in our modern scientific movement. The paths of detailed research have not attracted him, but he has sought in all ways to develop an optimistic vision of the world in harmony with the opinions of science, and he has interpreted bits of that vision in such a way as to become in a very real sense the father of modern geography, of modern civic studies, and of a great deal of modern sociology, and of much that is hopeful in modern education, while his vision of the nature and associations of sex in evolution is penetrating into many minds. Geddes has described himself as the boy who pulls the bell and runs away, and this is in a measure true, because he is always seeking the whole vision and careful not to let himself be engrossed in some detail of it. Miss Defries has done a service to many scientific workers by her collection of the graphs and schemes of notation that Geddes so persistently scribbles on scraps of paper. We only fear that they need Geddes himself to interpret them. There is a warm and serious appreciation of Geddes by Israel Zangwill and Prof. J. Arthur Thomson, and Prof. Patrick Abercrombie. Mr. H. V. Lanchester and Sir Chimanlal Setalvad contribute supplements. It is unfortunate that the scientific world can bestow no honour that would quite fit the case of Geddes, though its debt to him is seen in the manifold utilisation and development of his thought, not seldom by workers who scarcely know his name.

ISSN:0028-0836    

DOI:10.1038/120032b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE author pr e basis of this work in the first instance for his own use, as he had experienced the handicap due to the lack of a comprehensive systematic manual of this kind. ?To enable the average zoologist to identify the genus of any Cestode he may find,? keys are provided to the subclasses, orders, families, and genera, and a separate key is added to the genera of larval forms. Under each genus is given a short diagnosis and the name of the type species, including its author and date. At the end of the work is a list of hosts, and under each host are noted the cestodes which have been recorded from it. An index to the generic and specific names of Cestoda included in the work, an index to hosts, and a list (22 pages) of the principal memoirs on Cestoda complete the volume. The last published works referred to are those of 1922, and the volume appears to have been printed in 1924 but has only recently been placed on sale. Since the MS. left the author?s hands, Ejsmont has shown that Sanguinicola?formerly and in this volume regarded as a cestode and forming the sub-class Rhynchostomida?is a trematode. rihe manual is carefully prepared and will be found useful by helminthologists, and by teachers and senior students of zoology who desire to determine cestodes which they find in the course of examination of mammals.

ISSN:0028-0836    

DOI:10.1038/120033c0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

THE first and second sections of this volume contain tables of the chromosome numbers of plants and animals. Reference is made easy by systematic arrangement of the genera. Tt so happens that for the three examples cited under the Culicida3 (mosquitoes)?Anopheles, Culex, and Theobaldia?the diploid number is six and the baploid three. The authors have omitted mention of Btegomyia fasciata, in which the diploid number is four and the haploid two. The section on heredity gives data and formuke on variation, correlation, mendelism, crossing, heredity in man (e.g. of disease and abnormalities). The part on developmental mechanics deals with embryogeny, regeneration, growth, and the effects thereon of thyroid and other extracts. The following section summarises the known effects of contact, flowing water, air currents, gravitation, heat, moisture, light, electrical and chemical stimuli. A short section follows on the colour sense of animals. Protoplasmic movement, con- tractile vacuoles and vital staining receive adequate treatment, and there is an extensive concluding section oii sea water from the physical, chemical, and biological point of view. An excellent subject- index to the four volumes occupies 209 pages.This volume and its three predecessors contain a great mass of carefully checked and organised data and formuhe relating to all branches of biology from which can at once be obtained the exact basis, so far as it is known, for the consideration of vital phenomena. References to the original sources are given, so that the reader knows where to obtain further details when necessary. The editors and the ninety-eight collaborating experts are to be warmly congratulated on the completion of what is undoribtedly a great work and a very helpful source of reference.

ISSN:0028-0836    

DOI:10.1038/120034b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

MR. ALFRED REHDER was custodian, under the late Prof. C. S. Sargent, of the Herbarium of the Arnold Arboretum near Boston, Mass. The Arboretum, which forms part of the botanical equipment of Harvard University, concerns itself exclusively with woody vegetation, in other words, with trees and shrubs alone. Mr. Rehder has been attached to this institution for many years, and its specialisation has enabled him to concentrate his studies on the subject of this new book. Certainly no one could be found better equipped for the work. To botanists in Britain he has long been known for his thoroughness, his conscientiousness and the care which characterises everything that comes from his pen. All these qualities are very evident in his new work. Whilst primarily intended for botanical students of the cultivated trees and shrubs of North America, the similarity of the climate of great areas of that continent to much of ours will render the work very useful to students in Great Britain. In fact, the great majority of the species dealt with are already cultivated in English gardens, and there is no work available in the English language which deals so comprehensively with the subject in a botanical sense as this. The author commences with a synopsis of all the natural orders and families and an analytical key to the families and aberrant genera. Their sequence is according to the system adopted by Engler and Pranti in their ?C Nat rliche Pflanzenfamilien ?; it commences, therefore, with the coniferal alliance and ends with the Composite. As each order is dealt with in turn, a key to the genera included in it is provided and under each genus is given a key to the species. All the more important species are adequately described, so that the student is furnished with complete facilities for identifying them.The value of such a work as this can only be genuinely estimated by continued use. It represents an enormous amount of labour, the information its nine hundred pages contain being remark- ably condensed. There can be no doubt that it will for many years remain a standard work. To those in Great Britain who hold more conservative views in the matter of nomenclature than many Americans do, and look askance at the revolutionary methods of naming plants which find so much favour there,. Mr. Rehder?s retention of old and well-known generic names is very welcome. His adoption of the International Rules involves the use of a considerable number of specific names that are unfamiliar, but a full synonymy and a complete index always provide a guide to the species he is discussing. We have nothing but praise for this book, and feel that the more it is used the deeper will become our sense of gratitude to the author.

ISSN:0028-0836    

DOI:10.1038/120035a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature