摘要:

IN his Norman Lockyer lecture, delivered on Nov. 21 under the auspic of the British Science Guild, Dean In e discussed the effect which the advance of scientific knowledge has exercised upon our modern notions of morality and our ideals of practical conduct it is difficult in a discussion of this sort of seperate re1igion from ethics, for in practice,kiee t y are closely intertwined, and the infiuen(e of scientific conceptions has perhaps been greer upon religious thought than upon moral tendencies. Science reveals a world incomparably vaster than was dreamed of in the days when the great religions were founded; it has relegated man and his works to a remote and obscure corner of the cosmos, robbing him of the proud position which he arrogated to himself as the centre and crown of creation. Science has, therefore, profoundly modified religious conceptions. Has it had an equal effect upon morality? It seems to us that the effect has been mainly indirect, acting through the changed conceptions of the cosmos which science hasimposed, and Dean Inge's remarks appear in general to support this view. Dean Inge discusses first the problem so clearly stated by Huxley in his famous Romanes Lecture. Huxley considered that the ethical process ran counter to the cosmical process, that the moral life must be a constant fight against the lower instincts and desires which man has inherited from his animal ancestors. Law and morals he considered to be necessary restraints upon the struggle for existence between men in society, and his final conclusion was that "the cosmos works through the lower nature of man, not for righteousness, but against it." Being a man of fine and strong character, and in many ways a typical Victorian, Huxley laid immense stress upon righteousness upon honesty and courage in thought and action and the paramount claims of duty. He was over impressed by the Victorian conception of Nature as red in tooth and claw, of life as a bitter struggle in which the prizes go to the strong and ruthless. The opposition which he set up between moral Victorian man in societies, and prodigal, careless, and cruel Nature, seems to us now too rigidly drawn. After all, man also, with all his finer desires and aptitudes, his creativeness in art and science and philosophy, is a part of Nature; and, on the other hand, some of the despised lower instincts which he shares with the rest of the animal world are the basis of courage arid self-sacrifice in man himself as well as in the lower animals. Protection of mate and offspring and sacrifice of self on their behalf are developments of the fundamental instinct of reproduction which is as powerful in man as in the lower animals.Dean Inge describes Huxley's position as one of radical pessimism, and he is far from sharing it. He does not think that we are forced to consider the universe as radically unfriendly. The main error of the Huxleyan view was that it considered the cosmic process apart from man. To do this is to despiritualise Nature. "The cosmic process," says Dean Inge, "is responsible for man as be is, with all his unselfish devotion to family, friends, and country, and all his pity and sympathy with the weak, all his idealism and belief in the unseen, as well as for those brute-instincts, which Read thinks are too often forgotten by moralists and reformers. We are not committed to anything so hopeless as a struggle against the cosmic process."As to the positive contributions which the scientific spirit makes to ethics, Dean Inge finds thee mainly in the influence exerted by the increased clarity and honesty of thought which are the result of free and unbiassed inquiry into the nature of things. Thus he thinks that we may expect to see a more exacting standard of accuracy in forming and expressing opinions. Signs of this influence of the scientific spirit are already to be seen even in theological controversy, where "in those churches which are affected by the scientific conscience, there is much less garbling of facts and vilification of opponents than there used to be." Science will help too in driving out superstition and the baser forms of supernaturalism. "Perhaps nothing has corrupted the Christian religion so profoundly as the unethical magic which in many different forms has pervaded it: and it all rests on this assumption that there is a supernatural order,' which from time to time suspends' the laws of Nature, breaking the natural sequence of cause and effect." True religion, sound ethics, and the spirit of science can make common cause in resisting such beliefs. So, too, though science has nothing directly to do with theology, it may do good service by showing the inadequacy and poverty of the cruder conceptions of God which have done more harm to religio and ethics than the assaults of dogmatic atheism. An interesting question is raised by Dean Inge's claim that the proof of our blood-relationship with the other animals supplied by the doctrine of evolution has led to a more humane treatment of animals. In countries where the Church has firmly resisted the evolutionary doctrine, animals are as a rule cruelly treated. No doubt there is truth in this view, but it does not seem to us the whole truth , for there have been in all parts of the world lovers of animals and kindly masters long before evolution was dreamt of. We hope, with Dean Tnge, that the influence of science, and certainly of scientific men, will be exerted against the wanton destruction of plant and animal life and against the ugliness which seems inseparable from a mechanical civilisation, but we feel that the driving force must come not so much from the spirit of intellectual inquiry as from asthetic and moral feeling.Dean Inge devoted an important part of his lecture to a consideration and advocacy of the eugenist position. It is here that the direct influence of scientific thought and of the results of scientific inquiry upon conduct and practice, and even upon political action, is most fully exerted. A very definite ethical problem is raised, which gives rise to much conflict of opinion. Science has shown the importance of taking long views, of providing for the future improvement of the race, and avoiding racial deterioration. Instancing the action taken by America in drastically limiting the immigration of inferior stocks, Dean Inge points out how profoundly this scientific point of view is beginning to affect practical morality and the conduct of human life. We do not propose to enter into a discussion of the eugenist case, on which there is much to be said both for and against, but we confess to some surprise in finding Dean Inge stoutly maintaining that the new eugenic morality is more Christian than the moral traditions of the pre-scientific age. This does not seem to us to be fully reconcilable with his own remarks quoted above about man and the cosmic process, where pity and sympathy for the weak are rightly ranked among the higher instincts of man. Has the over elaborate civilisation which is the product in the main of the scientific age really led to an increase of happiness or enhanced the dignity and value of the individual life? This is an important question which is dealt with in the concluding sections of the lecture. The mechanisation of human life has proceeded apace. "Civilisation the accumulation of experience and of tools seems to have brought intrinsic evolution to an end." Men are becoming the slaves of machinery and a slave is only half a man. Is there any cure for this state of things, any means by which man might recover his lost opportunities for a full and rounded existence ? And can science help towards this end?"It seems to me," says Dean Inge, "that science ought to advocate a return to much simpler conditions. A happy and healthy country would be inhabited much more sparsely than England is at present by a population mainly agricultural, with small towns well supplied with schools, colleges, and laboratories. The passion for production at all costs would die a natural death, since the market for standardised products, now artificially stimulated by all the arts of scientific advertising, would be comparatively small. There would not be much of mere drudgery, for we should still have our labour-saving machines; but the arts and crafts would not be strangled and exterminated as they often are now. The instinct of acquisitiveness has become a positive disease; it should be checked by the principle already enunciated, that no needs should be indulged beyond their biological justification. No one should be condemned to the ceaseless repetition of one simple act as his life's work; the human frame and nervous system are not adapted to such unrelieved monotony. It is the dullness and irritation of mechanical labour that drive men to alcohol, gambling, and Bolshevism."A rational simplification, such as is here suggested, of the present absurdly complicated and cumbrous organisation which we call civilisation is needed to give mankind scope to develop its powers some portion as men of science and philosophers, others as craftsmen and artists, and others again as good citizens and helpers of their fellow-men.

ISSN:0028-0836    

DOI:10.1038/120757a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

SHORTLY after the War, Capt. Pitt-Rivers took a course at Oxford in psychological and anthropological studies. Thus equipped, and undeterred by the fact that he would be re-traversing the field of research in which had laboured the late W. H. R. Rivers, one of the most brilliant of twentieth-century psychologists and anthropologists, he embarked for the South Pacific islands to undertake a further inquiry into the effect of the impact of alien peoples upon the indigenous tribes. The fruit of his researches is presented in this volume, which bears comparison with those of his famous predecessor for breadth of treatment of subject matter, and exceeds them in its clarity of expression and fearlessness of exposition. Capt. Pitt-Rivers's diagnosis of the complaint from which the primitive communities in Oceania are suffering, and his general conclusions regarding the effects of European exploitation and later well-intentioned British administration, are much the same as those of other objective observers; yet he achieves such novelty of treatment that his book must be read. There is a growing tendency among humanitarians in Europe and America to assume that native problems,' that is to say, native unrest and discontent, exist only in those territories where the native races are being dispossessed of their lands and exploited in the interests of white plantation owners and mining companies. They would reject the idea as preposterous that such exploitation, however cruel, may be less Iisastrous in its effects upon native morale than an intentionally benign administration or Christian missions. Such implicit faith have they in the perfection of our civil and religious institutions, so conscious are they of the uplifting' influence of the conventional codes of their own society when introduced among primitive peoples, that they are apt to ignore the possibility that those of the natives which are being catastrophically destroyed may be intrinsically more valuable to and more consonant with the natural development of native culture. It may shake their complacency to learn that "nowhere in the Pacific is the phenomenon of the disappearance of the aboriginal races more noticeable than in the islands of the Bismarck Archipelago, where European control last made its influence felt. In these Islands the rapid decline, even during the last twenty-five years, is well known and admitted officially." This cannot be attributed to "violence and starvation, and civilised drink and diseases," to which causes Lord Olivier alleges the decrease of native population is due. These, of course, are factors which cannot be disregarded, but there is little doubt, avers Capt. Pitt-Rivers, that the principal cause in certain parts of the world is the destruction of the "old-culture forms and environmental conditions in the endeavour- to impose too dissimilar a culture upon a people specialised by a long process of adaptation to particular conditions."If there is one quality which differentiates the genuine scientific worker from the rest of his fellows, it is his humility of approach to the problems which cOnfront him. When an anthropologist, for example, studies native problems, the existence of differences between tribes and the manifest differences between races do not lead him hastily to assume that one particular culture-form is superior to the rest and that it is in the best interests of all peoples that they should conform to that one. As Pitt-Rivers says, He studies native customs to discover their importance in relation to the social organisation of the people, and thereby discover what is essential to that organisation and the communal life of the tribe or race; to study their beliefs and their morality sympathetically in terms of their own thought, and without the desire to substitute for what is native something that is not native or adapted to native life." There are certain aspects of the social life of most of the communities over which we exercise tutelage which shock the average European. Nakedness and pre - nuptial licence, polygyny, consanguineous marriages, child-marriages, infanticide, are direct contradictions of our code of conventions. Consequently, when confronted with racial degeneracy and depopulation, we attribute them to such evil' customs. But, as Pitt-Rivers points out, these customs existed centuries before the advent of the Europeans, and apparently had no lethal effects. If the imposition of our conventions upon native communities, the introduction of our legal system, disciplinary, sanitary, and clinical measures, and our form of religion, are to be regarded as beneficial, there should be an increase of population. The hard fact is that in Oceania there is an obvious decrease.This decrease supplies the author with his thesis the lethal effects of culture-clash- and leads him to subject the native customs to searching analyses, more particularly those customs which we deem to be shocking. He defends polygamy and consanguineous marriages and discounts the idea that child-marriages and infanticide are intrinsically bad or lethal in effect among the communities where they are practised. Inbreeding, as he says, and quotes Westermarck in substantiation, has from the earliest historical times been practised most among kingly and chiefly castes, with the aim of maintaining the purity of blood of the ruling castes, Provided there is some motive and ideal of selection in mating, inbreeding is positively beneficial and not the reverse. Dealing with the effect of the Christian missionary, he says, "His first efforts are directed towards inculcating decency and modesty by creating a sense of shame. In other words, by inculcating flesh-consciousness and the virtue of concealment, the two sign-posts of Christian culture." The later chapters of the book embrace a good deal that is of more general interest than specific application to the Polynesians. Nevertheless, they will repay the most careful study even though we may not be prepared to accept some of his conclusions. The author has brought to the study of psychological factors a fresh mind. He challenges the latest work of Spearman on "The Abilities of Man" with no little skill. On the subject of extrovert and introvert types he is most illuminating. But best of all is his scornful denunciation of Puritan intolerance and its narrowing and retarding effects on European culture.Capt. Pitt-Rivers is least convincing when dealing with sex-ratio, where he argues from insufficient biological foundation. Some of the statistics he quotes upon which he builds his theory are inadequate to the purpose. Occasionally also he makes sweeping generalisations which are not applicable to every primitive community. With certain parts of West Africa in mind, where the tendency is for the peoples to live in enormous towns, we cannot agree that "it is acknowledged that the tendency of native races of barbaric cultures is towards decentralisation." Again, some of us cannot share his views with regard to a "White Australia." The experiment in white colonisation in Queensland appears to have been most successful so far.The publication of this volume can do nothing but good. It will shock the susceptibilities of many. That is an advantage. Anything which will arouse our colonial administrators from too smug complacency, anything which will persuade the Home authorities to select men for the Colonial service who have been trained to seek for knowledge, to regard the customs of the native peoples whose interests they should serve as an integral part of their culture and one of the greatest factors in determining their will to live, should be heartily welcomed not only by anthropologists but also by all other scientific workers, If a suggestion to. the author may be made, it is that he should now carry out similar researches in Africa. They are badly needed.

ISSN:0028-0836    

DOI:10.1038/120759a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

SO long as sound forms the most rapid means of communicating thought from one normal human being to another, the subject of acoustics cannot fail to be important. Nevertheless, after the time of the publication of the classical treatises of Helmholtz and Rayleigh, it received little attention until in recent years war and broadcasting brought new problems and raised many difficulties in the practical application of the older knowledge. A dreary feature of the pre-War text-books on the subject was the neglect of researches carried out after about 1890. It is therefore a great pleasure to find that Dr. Richardson's book is a wellbalanced account of the present state of knowledge in experimental acoustics rather than still another of what may be called the Rayleigh-without-tears type of book. We must not complain that in this volume there is too little of Rayleigh, that is, too little mathematical treatment, for the sub-title is A Physical Text-Book." The author claims that it covers all that a candidate for the. pass and honours degree examinations of British and American universities should need. In actual practice the English degree student can omit the subject of acoustics, and even if the subject is not omitted altogether there is not time for a full treatment such as is here given. The student needs rather a short book dealing with a few of the main topics together with laboratory experiments and problems for solution. Neither of the two latter are given in this volume. The book is more likely to be of service to the research student, the research worker, and the technician, as it is the only source of information in English of the results so far attained in any branch of the subject, together with copious references to the original papers. Since almost all the important work has been included, it is of interest to note the many problems which are still unsolved, due partly to the neglect of acoustics as a field of research. A fallacy exists in the minds of many physicists that in order to research successfully in this subject one must possess a musical ear.' When we see how such a genius as Helmholtz was misled by trusting to his ears, we cannot but wish that much acoustical research would be done by deaf workers, who would be almost compelled to attempt only quantitative measurements. In truth, the ear is not a scientific instrument, although it is a wonderfully sensitive apparatus, the powers of which are well summarised in the chapter on subjective sound. Much remains to be elucidated in the subjects of speech and of hearing.Another big unsolved problem is that of sound recording. The ease with which one can set up a light membrane, and by coupling it with a suitable optical system, obtain pleasing curves upon photographic films, has misled many workers into thinking that the curves represent the impinging sound waves. Dr. Richardson rightly concludes that the phonodeik is the most accurate sound recorder of the phonograph type, but even this wonderfully delicate instrument was calibrated by a set of organ-pipes, and it was recently stated that at the National Physical Laboratory the organ-pipe as a standard source of sound had to be abandoned. The author shows kindness in omitting to mention one big memoir describing work in which gramophone records were used to study sound waves, and in which the method was fallaciously claimed to be good because by playing the record upon a gramophone and listening to it one could tell how nearly the indentations of the record represented the actual sounds originally recorded. It is safe to say that at present we have neither a perfect recording instrument nor a trustworthy standard source with which to test our imperfect instruments. Such as we have are well described in the chapter on analysis of sound in air. One should have liked a fuller treatment of the condenser microphone, including that of H. Riegger, which differs considerably from the Wente type mentioned. An adequate treatment would have required a good deal of space, but the subject is important, for distortionless amplification would have many valuable applications. Electrical devices in general have 1ready been of great service in acoustical research. The best attempts described in the book at absolute energy measurements, which are so difficult because of the minute absolute value of the energy of a sound wave of normal intensity, all depend upon electrical devices. In almost every chapter occur references to the use of electrical instruments such as the electro-magnet and the valve for maintaining the vibrations of tuning-forks, diaphragms, bars and strings, the oscillograph, the Einthoven string galvanometer, the stroboscope, the piezo-electric oscillator and instruments depending on the change in the electrical resistance of a heated wire over which sound waves pass. As in so many other branches of physics, photography also has given much help, particularly iii the recording of vibration and in the instantaneous spark photography of density changes in vibrating gases.Special chapters are devoted to heat-maintained sounds and to eolian tones, the latter chapter wisely preceded by a discussion of vortex formation and Prandtl's work on viscous fluids. This had not previously found its way into the text-books of physics, despite the test of twenty years' successful application in aeronautics. Well-written sections dealing with the various musical instruments are included. It might perhaps be better to omit such chapters from physical text-books, as their interest is more restrictcd than other branches of acoustics and their inclusion helps to spread the fallacy that acoustics is a subject for the musical physicist only. To such the meagre information available is merely a source of irritation. Because we have a good deal of knowledge of the motions of bowed and struck strings, we must not assume that we understand the acoustics of the violin or the pianoforte. A gut violin string radiates none of its energy to the air, and a steel piano string radiates but little. There are many complex changes between the string and the listener's ear. The problem of the special properties of a good Strad violin still defeats us. The strings clearly do not hold the secret, for they are the same as are used upon any violin. Musical acoustics is best treated as an intimate mixture of physics, physiology, and psychology.The book is very readable; is well produced, and can be heartily recommended to all interested in the subject. Technical readers with little or rio mathematical knowledge will have no difficulty in following almost the whole of the treatment. The honours degree student should use also the mathematical treatments of Lamb or Crandall ("Vibrating Systems and Sound," 1927), whilst the research worker will need also Auerbach's "Akustic," 1907, and the eighth volume "Akustics" of the Geiger and Scheele "Handbuch der Physik," 1927.

ISSN:0028-0836    

DOI:10.1038/120760a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN these two bulky volumes, Mr. Ash has for the most part succeeded in tracing the histories of practically all the domesticated varieties of dogs which are known at the present day. In an opening chapter on the origin and evolution of dogs as a whole, in which he quotes many well- known authorities, he puts aside Mivart's wolf- jackal ancestry theory in favour of a hypothesis that the ,ancestors of modern dogs probably existed in Eocene and Miocene times and were closely related to Cynodictus, Amphicyon, Simicyon, and Cynodesmus. It would seem, however, that in view of the rapidity with which change takes place in animals under domestication and artificial selection, there is no necessity to go back very far beyond historic times to find the ancestor of the modern dog, in all its variations, among the wolves and jackals, especially when one considers, as Mr. Ash points out later on in his second volume, that breeds so different as the Yorkshire, the Airedale, and bull terrier have all been made during the past hundred years, and that the so-called Alsatian wolf-hound, more properly known as the German sheepdog, has only been in existence a little more than a quarter of a century. Again, a comparison of some of the figures of typical dogs of a hundred years ago with those of their modern representatives shows that the type in many cases has changed to such a marked degree that the two might easily represent entirely different breeds. On the contrary, where the type became stabilised many years ago and artificial selection has been carefully carried on by man, as in the ease of some of the members of the greyhound group, which are one of the oldest of all breeds, there appears to have been very little change in general appearance between the dog of to-day and those of 6000 years ago.In view of the publicity which has been given to Alsatians in the daily press of late, it is interesting to note that Mr. Ash says: "There seems to me to be little doubt that the Alsatian type was obtained or developed at some distant time by wolf and/or dingo crosses," and goes on to quote that the greatgranddam of the famous Alsatian "Hector Von Wohlen" was the result of a cross between a dog- wolf and an Alsatian bitch. The book is not written merely for the technician; it will have an appeal for all dog-lovers, for Mr. Ash's researches have led him to study the dog from many aspects. There are chapters on dogs in relation to religion, medicine, law, and history in general. We learn that in Wales a certain cure for a cough is to put a hair of the patient's head between two slices of bread and give the sandwich to a dog, and also that the hair of a dog when burnt is a sure remedy when applied to a bite. The Chinese seem long ago to have come very near to Pasteur's great discovery: "If. a man was hurt by a mad dog, then the man goes mad, the best cure was to use the brain from the same dog and put it on the wound."As a work of reference the dog breeder will find Mr. Ash's book invaluable, for in addition to the histories of all breeds, there are lengthy appendices in which show points, pedigrees of famous dogs, and championship winners are given. The book is worthy of a bibliography and it is to be regretted that none is given, the only references being scattered notes in the text and rather inadequate footnotes. There are more than 150 excellent plates, in which are figured several hundred dogs, from those of ancient Assyria and Egypt down to the living championship winners of to-day. These have been collected from many sources, and they alone testify to the care and perseverance which have gone to the building of what will doubtless be a classical work on dogs and one which should find its way to every good reference library, as well as to the shelves of every dog-lover who can afford it.

ISSN:0028-0836    

DOI:10.1038/120762a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

DREDGERS are an extemely varied, albeit highly specialised, type of vessel, interesting alike to the naval architect, the engineer, and the shipbuilder. Literature on the subject of dredger design is, however, far from voluminous and, indeed, is remarkable mare for its paucity than for its fullness. There is abundant scope, then, for the volume by Mr. Dekker, and hfs description of a number of present-day dredging vessels and appliances forms a useful addition to the reference library of the practising engineer. It will b felt, on perusal, that the book is, in fact, mainly descriptive, and that it concentrates largely on iiidivkluai examples of dredger construction. This does not detract from the utility of the work as a practical directory to the subject, but it still leaves the field open for a dissertation on the principles underlying dredger design. Such a work would, perhaps, be the special province of the naval architect. Mr. Dekker's book is not divided into chapters, but is iii two parts, with numerous sub-sections. Commencing with a historical rsum and account of early types, the modern bucket dredger is then subjected to analytical description, followed by similar treatment of the sand pump, the suction dredger, and the suction cutter dredger. There is no reference to the dipper dredger, the type so prominently in vogue in North America. No doubt this is due to the author's Dutch nationality and his intention, expressed in the preface, of giving solely an account of the development of dredging appliances in Holland. He points out that " as regards the more recent development, England and Holland may safely claim to have made the greatest progress." A number of interesting photographs and line drawings enhance the attraction of the book.

ISSN:0028-0836    

DOI:10.1038/120763b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

In this paper-covered pamphlet of eighty pages, which is sold for 4tnce, Prof. Rice sets forth the doctrine of relativity: and not only this, but also (as prelimiriaries to it) the principles of Newtonian physics, he history of optics in the nineteenth century, and the Maxwell-Lorentz theory of electricity. It is a wonderful performance judicious, scholarly, well written, and sparkling with apt comparisons and illustrations. A little masterpiece in every way. In the expectation that it will be continually reprinted, and translated into every language under the sun, we venture to point out one or two things which might be amended. On page 13, after correctly describing FitzGerald as an Irish physicist," the author refers to Larmor as " an English mathematician at Cambridge." Larmor is, however, another Irishman. On pages 51-52 we are told that the mass of the electron has been proved by experiment to be wholly electromagnetic: we do not understand what Prof. Rice means by this: at any rate, the Kaufmann-Bucherer experimerits on the mass of /3-particles merely show that their mass varies with velocity in the way that any mass, whatever be its origin, must do according to the relativity theory. On page 73, latitude is obviously a slip for longitude.

ISSN:0028-0836    

DOI:10.1038/120764b0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

IN a letter to NATURE, published July 23, 1927, I showed, on the basis of experimental evidence, thatPuccinia helianthiis heterothallic. The results of further experiments now enable me to state definitely thatPuccinia graminisis also heterothallic. Moreover, since my first letter was written, proof has been obtained that the pycnia (spermogonia) of the Rust Fungi are not, as many botanists have supposed, male conceptacles producing non-functional spermatia, but are active organs having a non-male function which they carry out through the agency of flies. This discovery was made as follows.In May, 1927, I had a large number of sunflower seedlings, upon the young foliage leaves of which there were mpny pustules of Puccinia helianthi. Each pustule had originated from a single sporidium and had numerous pycnia on its upper surface, and every pycnium had excreted a drop of nectar containing pycnospores. Theoretically, as set forth in my former letter, it seemed reasonable to suppose that the mycelium, pycnia, and pycnospores of some of the pustules were (+) in sex, whereas the mycelium, pycnia, and pycnospores of other pustules were (in sex. On May 17, Prof. A. H. Reginald Buller, of the University of Manitoba, was in the greenhouse of the Dominion Rust Research Laboratcry inspecting the experiments in progress. A solitary fly, one of the first to appear after the winter season, had entered the greenhouse. Prof. Buller directed my attention to the fact that the fly was settling on the sunflower leaves, sipping nectar at the pycnia of one pustule and then flying off to another leaf and sipping the nectar of the pycnia of another pustule, and he at once said: "The solution of the problem of the function of the pycnium is an entomological one. Copy the action of the fly. Take (+) pycnospores to (-) pycnia and () pycnospores to (+) pycnia, and may well be that the pycnospores will germinate and bring on the diploid phase of the mycelium, evidence of which will be given by the development of ecia and eciospores on the under side of each pustule." This suggestion has been tested experimentally during the past suminei and its excellence has been amply demonstrated. The experiments bearing on the function of the pycnia will now be set forth.In two sets of experiments with Puccinia helianthi on sunflower leaves, pustules of monosporidial origin, each pustule having developed numerous pycnia but no ecia, were treated as follows: in 184 pustules the pycnos.pore-containing nectar was mixed with the help a scalpel, the nectar of any one pustule being mixed with nectar of several other pustules; while, a control, in 174 pustules the nectar of each pustule was stirred up with a scalpel, but not mixed with any other nectar, the scalpel being carefully sterilised before each operation. Five days after the experiment had begun, the condition of the pustules was es follows: of the 184 mixed pustules 176 had produced ecia, 4 no ecia, and 4 had wilted and died through leaf-injury; of the 174 unmixed pustules only 20 had produced ecia, while 154 were entirely free from acia. Under normal conditions when the nectar is neither mixed nor stirred, a certain percentage of monosporidial pustules always produces ecia, as already recorded in my first letter: The appearance of eecia in 20 of the unmixed pustules was therefore in agreement with expectation.From the experiments just recorded it is clear that mixing the pycnospore-conbaining nectar leads with rapidity and considerable certainty to the development of acia. While the pycnospores are haploid, the leciospores are diploid. We can therefore also say that mixing the pycnial nectar causes each pustule of monosporidial origin to change from the haploid to the diploid phase. FIG. 1. Under side of a sunflower leaf. x 1.Experiments similar to those just described have been made with Puccinia graminis on barberry leaves. In one set of experiments the pycnial nectar of 116 monosporidial pustules was mixed; while, as a control, the pycnial nectar of each of 85 monosporidial pustules was stirred up separately but not mixed with any other nectar. Six days after the experiment had begun, the condition of the pustules was as follows: of the 116 mixed pustules 102 had produced lecia and 14 no lecia; whereas of the 85 unmixed pustules only 17 had pro. duced eecia, while 68 were free from acia.In the experiments with Puccinia graminis just described we again have clear evidence of the function of the pycnia; for, when the nectar is mixed, acia are rapidly formed in most ofthe pustules, whereas when the nectar is not mixed, most of the pustules do not develop acia. A certain percentage of unmixed pustules always produces acia, as in Puccinia helianthi. In Fig. 1 is shown the under side of a sunflower leaf. The leaf was inoculated with sporidia of Puccinia helianthi on July 9. Each pustule originated from a single sporidium and was therefore unisexual. On July 29 the pyonial nectar of the ten pustules on the right side of the leaf was well mixed; while, as a control, the pycnial nectar of each of the six pustules on the left side of the leaf was stirred separately but not mixed. On Aug. 3 the leaf had the appearance shown in Fig. 1, and on Aug. 4 the photograph was taken. This experiment again clearly demonstrates that the pycnia are functional, in that their pycnosporecontaining nectar, when transferred from one pustule to another, brings on the diploid phase as shown by the appearance of acia within five days of the transference.In Fig. 2 is shown the under side of a barberry leaf. The leaf was inoculated with sporidia of Puccinia gramini on Aug. 2. Each pustule originated from a single sporidium and was therefore unisexual. Up to Aug. 19 one pustule on the right side of the leaf had produced ecia. On that day. the pycnial nectar of all the pustules on the right side of the leaf was well mixed; while, as a control, the pycnial nectar of each of the eight pustules on the left side of the leaf was stirred separately but not mixed.. On Aug. 28 the leaf was photographed and had the appearance shown in Fig, 2. The effect of mixing the pyenial nectar is very evident; seem appeared on the right side of the leaf where mixing had been effected, but not on the left side where mixing had been avoided. Proof that flies mix the pycnial nectar of separate unisexual pustules and so cause the pustules to change from the haploid to the diploid phase, as shown by the appearance of acia, was obtained with Puccinia helianthi as follows:Fifteen to twenty flies were enclosed in a large screen-wire cage with about twelve pots of sunflower seedlings, on the foliage leaves of which there were 98 monosporidial pustules bearing pycnia but no secia. As a control, flies were kept out of another large screen-wire cage which contained fifteen pots of sunflower seedlings, on the foliage leaves of which there were 159 similar pustules. Pie. 2 Under side of a barberry leaf. x 2, Eight days after the beginning of the experiment 96 of the 98 pustules to which flies had had access had produced secia and only 2 pustules no ecia, whereas only 5 of the 159 pustules to which flies had not had access had produced acia.It was found that in Puccinia helianthi, and also P. graminis, nectar which had been heated to 700 to kill the pycnospores is not effective in inducing the production of ecia when mixed with the nectar other pycnia on the living leaf. This indicates that it is the pycnospores which are the effetive agents in inducing the formation of aecia, and not the nectar.In a series of experiments with Puccinia hetianthi, and in another series with P. gramini, the pycnial nectar of one monosporidial pustule was removed in capillary tube and divided into several drops, and then the drops were applied singly to the pycnia of as many pustules as there were drops. In response to this treatment some of the pustules produced secia and others did not, thus indicating that the pycnospores are of two kinds, (+) and (). The full details these experiments will be recorded elsewhere. It appears that, under natural conditions, there are three ways in which pustules of monosporidial origin may change from the haploid to the diploid condition:(1) by a (+) sporidium and a (-) sporidium settling a leaf lose together, so that they form pustules which coalesce in such a way that the (+) mycelium and the () mycelium come into contact directly; (2) means of flies which carry (+) pycnospores from one isolated pustule to the () pycnia of another isolated pustule or, conversely, () pycnospores of one isolated pustule to the (+) pycnia of another isolated pustule; and (3) spontaneously. The cause of the spontaneous change of a certain number of the pustules of Puccinia helianthi and of Puccinia gramini from the haploid to the diploid condition is at present unknown, but the phenomenon finds its parallel among the Hymenomycetes in Coprinus radians investigated by Van- dendries and in C. Rostrupianus investigated by D.Newton. , .The pycnia attract flies and reward them for their visits in very much the same way as do flowers or the Stinkhorn Fungus. They occur chiefly on the upper side of the leaves, where they are readily accessible to insects; they are usually yellow or red in colour, by which means and perhaps also by the refraction and reflection of light in the drops of nectar they are made conspicuous; in some species, e.g. Fuccinia $uaveolens, and possibly in many, they emit an attractive odour; while, finally, the nectar contains sugar, and on this account is sipped by flies with avidity. It has long been remarked that, in those rust fungi which possess them, the pycnia are the first spore- producing organs to appear. Since they play such an important part in changing the haplophase into the diplophasc and in inducing the formation of acia, their appearance on the mycelium before the wcia can now be readily understood. Pycnia precede ecia, because by pycnial action ecia are formed.The crossing of two physiological forms of Puccinia gramini$, etc., might be effected in the following relatively simple manner; obtain monosporidial pus tules of both strains and then mix the pycnial nectar of a (+) pustule of one strain with the nectar of a () pustule of the other strain, or, conversely, mix the nectar of a () pustule of one strain with the nectar of a (+) pustule of the other strain. In my previous letter to NATURE T stated that, in Fuccinia helianthi, the eciospores which had appeared in at least some of the acia of pustules of monosporidial origin are uninucleate. Further cytological experience has convinced me that the apparent uninucleate condition of these eciospores was due to an artefact. The young eciospores near the spore-bed of every acium of monosporidial origin that I have investigated more recently have all proved to be binucleate.In conclusion, I desire to thank Prof. Buller for assisting me with valuable suggestions and helpful criticism.

ISSN:0028-0836    

DOI:10.1038/120765a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

Two different types of X-ray diffraction patterns and their interpretations, made from cellulose fibres, have appeared in the literature; one associated with a ‘point diagram,’ presented by R. O. Herzog,1the other, with a ‘line diffraction pattern,’ by the writer.2Although the two methods used were slightly different, both depend upon reflection of mono- chromatic X-rays from the uniformly spaced planes of atoms in the fibres, and shouldtherefore be capable of identical interpretation. The data in general are in fair agreement, except in two or three examples where the differences cannot be accounted for by experimental errors. It is the purpose of this communication to direct attention to this lack of agree- ment, and to point out its effect upon the lattice structure proposed by Herzog. the Journal of Physical Chemistry, April 1926, pp. 455-467, Herzog discusses a lattice for cellulose which he considers a revision of his earlier work. In the data for this revised lattice there appears a series of interference points which are associated with planes parallel to the c axis of the elementary cell; that is, planes parallel to the long axis of the fibres. In that series particular attention is directed to points A3 and A4. The data given below were taken from his Table I., and from them the interplanar spacings d were computed by means of the Bragg formula:nX = 2d sin 0, where 0 is the glancing angle, and A = 154 A. the K wave-length for copper, since the radiation usedwas from a copper target. Point. Sin 6. d.A3 017909 430A. A4 01981 389In the other type of diffraction pattern, as published in the Journal of General Physiology, Nov. 1925, pp. 221-233, and May 1926, pp. 677-695, I found no line corresponding to the 43O interplanar value for planes which were parallel to the long axis of the fibres. In making these patterns the X-ray beam was passed through a filter to ensure a monochromatic beam of K wave-lengths only. When, however, diffraction patterns were made later with the unfiltered radiation, line which corresponded to the 430 value always appeared prominently. Since this interference maximum failed to appear when Ka wave-lengths only were used, and oh the other hand always appeared clearly when the beam was a composite of all of its wave-lengths, it was suspected immediately that a single set of planes with strong reflecting powers had produced two interference lines, one from the Ka, the other from the Kp wave-lengths. Calculation shows that the point A3 might have been produced by the Kp wave-lengths from the very strong 389 planes;K,4 K0 X=1'54 A. a=139 A.4'30 389 389Point. SinS,A3 017909 A4 0-1981and since no line was found corresponding to the A point when the Kp wave-lengths were filtered out of the beam, one must conclude that Herzog failed to recognise the K0 origin of the A3 point and gave it the 430 value as though it were of K5 origin. That value, therefore, should be discarded from the data. Attention was directed to a similar use of a K0 interference point (NATURE, Aug. 15, 1925,p. 243) in the original data of Herzog and Janeke which was published in Zeitsch. for Physik, 3-3, 196-198, 1920, and in which incidentally this 430 value does not appear. That value apparently had been discardedat that time as of K0 origin. When, however, one attempts to discard the 430 value now, a new importance is found placed upon it. The dimensions for the axes of the revised elementary cell as proposed by Herzog are given as a: b: o860: 778: 1022. This elementary cell may be represented by Fig. 1, where OA'a=860=2 x 430OB=b=778==2 x 389. The two planes passing through Q and A respect- ively and parallel to the plane OBC are considered as being separated by the 430 distances, OQ and QA. Likewise OR and RB are the 389 distances. That the a axis is directly associated with the 430 value and the b axis with the 389 value is definitely fixed by the indices (200) and (020) respectively, given in his Table II.It seems, then, that the values used for the a axis and the b axis of the elementary cell proposed were both produced by the same set of planes, and when the 430 value is discarded, as it seems evident that it must be, the axial dimensions proposed by Herzog lose their significance, and therefore a number of conclusions must be discarded. (1) That four anhydro-glucose units are contained in the elementary cell is now of course without foundation. (2) The assumptions that certain " interference maxima are produced by impurities in the fibre, or that there are two types of carbohydrates embodied in the cellulose of the fibre, are now also without adequate basis. (3) The correspondence between the 430 value and a certain interference maximum obtained from mercerised cellulose likewise now has no significance. These conclusions at least must be discarded if the only basis for them lies in the elementary cell as suggested by Herzog. A lattice based upon the line diffraction patterns' seems to be in better agreement with the properties of the fibres, both physical and chemical. This structure is discussed in detail by Sponsler and Dore in "Colloid Symposium," Monograph 4, pp. 174-202, 1926, and in the papers mentione

ISSN:0028-0836    

DOI:10.1038/120767a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

WHEN We pub1ihed in NATURE an account of the discovery of Lowcr Pa1æo1ithic Implements in Ireland, we expected that the announcement would give rise to a certain amount of disturbance among the more old-fashioned archæologists of that country, but we did not contemplate, or believe it possible, that the announcement would result in the appearance (NATURE, Nov. 5, pp. 652–3) of such a series of statements as that to which Prof. Macalister and hi associates have been so unwise as to append their signatures. Incredible a it may appear, it is nevertheless a fact, as is clear from the particulars published in NATURE (Nov. 5), that these investigators have not even correctly located the site at Rosses Point, Sligo, where the collapsed rock shelter exists, the details of which, as given in NATURE (Aug. 20), are preserved in excellent photographic and other records, which are to be made public shortly in the memoir to be published by us, but have mistaken the promontory of The Rosses for Rosses Point, which constitutes the northern projection of the former. Prof. Macalister and his associates clearly indicate in their note in NATURE that they visited this spot unknowingly, and thus failed to observe the collapsed rock shelter—or the Raised Beach of powdered shells. In view of this faulty observation it is not urpriing to find that these investigators state that “there is no Raised Beach … in the district.” This claim, however, is in direct opposition to the opInion expressed in the Geological Survey Memoir, “The Counties of Sligo and Leitrim,” p. 27.Prof. Macalister and his associates are clearly, there. fore, engaged in the abortive task of attempting to criticise a site which has not been dealt with by us, When they were confronted with the fact of the discovery of pakeolithic implements in (a) a rock-shelter, and (b) Boulder Clay in Sligo, the only course they could take in order to support the ancient order of archamlogy was quite obvious. All they imagined must be done was to deny that the rock-shelter is ancient, and that the specimens found in it, and in the Boulder Clay, are humanly flaked. It is true that these are matters open to discussion, but we have confidence that competent rcheologists, not unscientifically deter- mined to deny the presence of palamlithic implements in Ireland, will give little heed to the arguments and assertions of Prof. Macalister and his associates. In fact, all , those with the requisite knowledge enabling them to give a judgment of value upon the matter have, without one exception, at once accepted the Sligo specimens as of human origin. As an example of the confusion of thought of our opponents, it may be pointed out that in neither of our notes to NATURE did we refer to the Mousterian culture as of Early Pakeolithic age. Yet we are informed that such a relegation is untenable. We fail, also, to appreciate the relevance, or importance, of the statement that Mousterian artefacts are not as rule of impressive size. Do our critics wish to suggest that this prevents the Sligo specimens from being regarded as of this age, and further, do they claim that the examples of very large implements from High Lodge, Suffolk, and other places, including Le Moustier itself, are also barred from a Mousterian status? As for the assertion that the change of colour produced on the surfaces of stones by weathering is not to be described as patination,' this is a dogmatic claim unsupported, as are most of the statements contained in the note under discussion, by any evidence.It is not for us to explain why the paheolithic people of Sligo chose to flake limestone into implements, or to give reasons why the efforts of Prof. Macalister and his associates failed to produce a conchoidal fracture in this material. But the fact remains that the ancient people did both these things, not once but many times, as may be seen by an examination of the material collected in Sligo, and exhibited at the rooms of the Society of Antiquaries of London until Dec. 6. We, of course, regret that our critics failed to find any artefacts when visiting the Sligo coast, but this is possible of explanation on two grounds: either that the previous searching was so thorough as to leave nothing to be found, or as is more probable because Prof. Macalister and his associates did not know what to look for and preserve. It is not necessary for any demonstration to be given of the manner in which the Sligo specimens were flaked, as a study of these by anyone familiar with the flaking of stone will show clearly, and beyond any question, that the method described in NATURE (Sept. 24) was indeed carried out in ancient times. Further, it is to be doubted even if such a demonstration were given whether Prof. Macalister and his associates would understand it. They are evidently unfamiliar with the Mousterian technique by means of which Levallois flake-implements were detached from prepared cores. The Sligo method with two minor differences is absolutely true to type, yet our critics describe it as complex.' This it may appear to them, but it is otherwise with archeologists who have made a study of these matters.Prof. Macalister and his associates, with a thorough- going disregard of ordinary scientific procedure which would have necessitated an examination of the Sligo specimens before passing judgment upon them, nevertheless do not shrink from inferring, in the columns of NATURE, that they are of natural origin. On the other hand, their supporter, Mr. Warren, regards the same specimens, with the exception of those found in Boulder Clay at Ballyconnell, as made by man. This, to say the least, is unfortunate, especially in view of the inherently bad case which our critics have to defend. Lastly, we may direct attention to Mr. Warren's statement that, apropos of the Sligo material, there is " no passable resemblance in any one of these flakings to any form of prehistoric implement, either pakeolithic or neolithic." This strange claim is indeed a classic example of the truth of the saying that given sufficient rope, certain people are bound to hang themselves. Anyone interested in this matter who has visited the exhibition of the Sligo specimens at Burlington House will, we have no doubt, agree with us that Mr. Warren, together with Prof. Macalister and his associates, have suspended themselves in a very thorough a

ISSN:0028-0836    

DOI:10.1038/120768a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature

摘要:

ACCORDING to various natives from different places on the shore of the Victoria Nyanza, many of the lake fishes (all except the silurids, according to one fisherman) carry their fry in their mouths. One variation of the story makes the eggs pass internally from the ovary to the pharynx: in another the eggs or fry are gathered up from the nest in ease of danger.The account was received with almost the same caution accorded to the story of the monstrous serpent of the lake, but it has been found to apply to several cichlids. Eggs have been found in the mouths of Haplochromis macroclon (at Kisumu from a small native papyrus seine on Aug. 17) and H. nubUus (at Bukoba from a cast-net on Sept. 7). Newly hatched young were found in the mouth of one specimen of H. nubilus taken in a cast-net at Bukoba on Sept. 6. Two specimens each with young advanced beyond the stage of complete absorption of the yolk-sac were taken in the same manner Ofl Sept. 6 and 7. One Tilap'ia variabilis taken from a large native papyrus seine at the mouth of the Kibos River near Kisumu on Aug. 14 had young in its mouth with the yolk-sac almost completely absorbed. Advanced young were taken from H. crassilabris at Kisumu on Aug. 17.One haul with a seine on Rusinga Island at the mouth of the Kavirondo Gulf on Sept. 1 yielded 19 cichlids. Seven of these had eggs or young in their mouths. These were placed in an aquarium, and included various stages from eggs which hatched within an hour to young in which the yolk-sac was completely absorbed. The seven fish were: one Macropleurodus bicolor, five Haplochromis nubilus, and one H. ishmacli. On Aug. 24 one H. ishmaeli was kept alive of two taken with young in the mouth. This fish and its fry were placed in an aquarium, and towards evening it was observed that the fry had gathered up into a fairly dense shoal near the parent's mouth and their apparent number had decreased. Parent and fry died shortly afterwards.In all cases the parent concerned was the female. The Tilapia parent and young were kept in a vessel for one week. Although the fish was not supplied with food, the young were not eaten, which is not in keeping with a theory that the fish taken with small fish in the mouth were caught in the act of eating them.In several cases the mouth of the mother was packed quite full of eggs or young, so that the soft part of the lower jaw was noticeably distended. The nomenclature used herein is after Tate Regan (Proc. Zoo. Soc., 1922).

ISSN:0028-0836    

DOI:10.1038/120769a0

出版商:Nature Publishing Group    

年代:1927

数据来源: Nature