IF F this work fails to bring about that revolution in biological science which its announcement led us to expect, it is not for lack of confidence on the part of the authors or their publisher. We were informed (by advertisement) that with the exception of a certain well-known treatise by de Vries this book was "the most important contribution to biological science which has appeared since Darwin's Origin of Species.'" We were further told that "the authors have no difficulty in demolishing some of the theories which are most cherished by biologists of to-daynotably those of mimicry and recognition markings in birds," and that "the facts which they have brought together undermine the whole of the massive superstructure which Neo-Darwinians have erected on the foundation of the theory of natural selection." A few extracts from the preface will suffice to reveal the tone which pervades this latest attack upon the theory of natural selection "We fear that this book will come as a rude shock to many scientific men. . . We are endeavouring to save biology in England from committing suicide, to save it from the hands of those into which it has fallen. . . . The Wallaceians (sic) continue on their course and give to the world a spurious Darwinism ... we were both of opinion that biology is in an unhealthy condition, especially in England, and that the science sorely needs some fresh impetus." After such a flourish of trumpets we naturally turn eagerly to the text for the "fresh impetus," but fail to find inspiration. There are many gibes aimed at and epithets attached to "Wallaceians” and “NeoDarwinians," and there are some very remarkable perversions of the history of organic evolution. The authors set out, in fact, with an attempt to explain the reasons why the "Origin of Species" was accorded a rapturous welcome .. by the more progressive biologists," and how "the man in the street was able to comprehend the theory of natural selection. This was greatly in its favour. Men are usually well disposed towards doctrines which they can readily understand." Those who are familiar with the history of the publication of Darwin's great work and the difficulty which he experienced in making even the expert naturalists of his time fully grasp the principles of the selection theory will wonder from what source the authors have derived their information. As another example of historical perversion, attention may be directed to the statement (p. 198) "that all the opposition to the theory of protective colouration comes from those who observe nature first hand, while the warmest supporters of the theory are cabinet naturalists and museum zoologists." From this the reader will infer that the founders of that theory, Bates and Wallace, Trimen, Belt, Fritz Müller and Weismann, were not, in the judgment of the authors, observers of nature at first hand. 66 Within the limits of an ordinary review in these columns it is impossible to discuss in any detail the large body of evidence which the authors bring together in order to "demolish" those whom they dub "Neo-Darwinians," Wallaceians," or even, when their scorn reaches its highest pitch, "NeoWallaceians." The general drift of the work is purely destructive, and its main object is apparently to disprove the all-sufficiency of natural selection. There is nothing very novel in this position, and by attributing to the followers of Darwin and Wallace a highly exaggerated and super-exalted doctrine, which no Darwinian has ever upheld, such refutation is naturally a very simple matter. The authors appear to imagine, for example, that somebody holds the belief that the theory of natural selection has been seriously held " to explain all the varied phenomena of nature" (P 28). Of course, the very obvious and flagrant cases of adaptational colouring coming under the designations "protective resemblance" and "mimicry," which have generally been looked upon as reasonably explicable on Darwinian principles, come in for a large share of attention, and here is the verdict with respect to these theories: "We have examined these mighty images of gold, silver, and brass and iron, and found that there is much clay in the feet. We shall devote this chapter to lifting the hem of the garment of sanctity that envelops each of these images, and so expose to view the clay that lies concealed" (p. 172). It must be left to the reader, whose flesh has been made to creep by this preliminary threat, to find out how far the authors have succeeded in damaging the evidence which has been accumulated by the joint labours of some of the most acute observers of nature ("at first hand "!) since Darwin gave us the key to the explanation of the phenomena in question, half a century ago. Prof. Poulton, as one of the most prominent of recent workers in this field, comes in for much castigation. The methods of demolition adopted by the authors have been made quite familiar by anti-Darwinians ever since the publication of Mivart's "Genesis of Species." Cases of convergent are non-mimetic are marshalled characters which against the selection theory of mimicry, the facts of mimicry are altogether denied or said to be much exaggerated, and cases of obvious adaptation, such as Kallima, are said (virtually) to be too good to be true, or, in other words, that the imitation is elaborated to an unnecessary extent. It will naturally be asked whether this great array of objections and difficulties is a purely destructive attack, or whether it is a prelude to some great constructive generalisation. The reader who looks for new light will, we fear, be disappointed, judging from the following specimen of an "explanation" of the mimicry of butterflies by diurnal moths : "When two species adopt the same method of obtaining food, it not infrequently happens that a professional likeness springs up between them " (p. 250). In so far as there is any positive declaration to be found in the volume the authors may be classified with the "mutationists." They are at great pains, in fact, to define their precise position as members of that school "of which Bateson, de Vries, Kellog, and T. H. Morgan appear to be adherents " (p. 26). They state further that, "like Darwin," they "welcome all factors which appear to be capable of effecting evolution" (p. 27). What these factors are beyond natural selection (to which they assign some value) it is not quite easy to gather from the present work. Isolation, correlation, variation, and heredity have been considered very seriously by all evolutionists from Darwin down to the present time, and it cannot be said that Messrs. Dewar and Finn have shed any new light on these subjects. They tell us (p. 387) that species are made by the inherent properties of protoplasm and the laws of variation and heredity. These determine the nature of the organism; natural selection and the like factors merely decide for each particular organism whether it shall survive and give rise to a species." 66 This will seem to the reader who is not a "mutationist" to be very like pure Darwinism with a dash of" inherent properties of protoplasm "thrown in. The introduction of 'biological molecules," which are defined (pp. 157-9) as the units of which the germ cell is composed, may be considered as the substitution of a vague conception for the very definite mechanism which has been introduced into the theories of heredity associated with the names of Darwin, Herbert Spencer, Weismann, Mendel, and others. One example of the use of this conception will suffice to show its vagueness :— a certain number of illustrations derived from personal THE GEOGRAPHICAL DISTRIBUTION OF LEPIDOPTERA. Die geographische Verbreitung der Schmetterlinge. THE HE author of this work is one of the older German entomologists, who has been working for many years in the formation of a collection of Lepidoptera, and has published many valuable lists and monographs of the species found in various limited regions. He has now utilised his materials in a work which cannot fail to be interesting, not only to entomologists, but also to all naturalists who direct their attention to the numerous problems connected with the present geo"Thus the phenomena of mimicry' and 'rever-graphical distribution of animals over the surface of sion are, we believe, due to the fact that in the fertilised egg of both the pattern and its copy a similar arrangement of biological molecules obtains. If we regard the sexual act as resembling in many respects a chemical synthesis, the phenomenon need not surprise us (p. 293). The reasons for associating mimicry with reversion and sexual reproduction are not very obvious, even from the authors' own point of view. Dealing with the first set of phenomena only, if the "explanation" means that in a mimic and its model the similarity of colour and pattern is due to an identity either of physical structure or chemical constitution, or of both, it is untrue in fact. If it means that the resemblance has arisen because the units (i.e. "biological molecules") of which the ovum is in each case composed give rise to a similarity of colour and pattern on development, this appears to be a mere paraphrase of the description of the facts and no explanation at all. It is to be regretted that Messrs. Dewar and Finn have made this aggressive incursion into the domain of biological theory. They are favourably known as popular writers on Indian ornithology and other natural-history subjects. Although in the present volume none of the objections brought against natural selection are new in principle, it must be placed to the credit of the authors that, unlike so many of the earlier critics of Darwin's work, they are able to give the globe. Dr. Pagenstecher remarks that the geographical distribution of Lepidoptera, like that of plants, is closely connected with certain physical and organic factors. The most important physical factors are (1) soil; (2) temperature and light; (3) moisture; (4) atmospheric conditions. The first portion of this work is therefore devoted to general observations on the geographical conditions of the continents, and the influence of mountains, desert or fruitful plains, the neighbourhood of rivers and seas, continental and oceanic islands, &c., on distribution. The influence of temperature, moisture, atmosphere, &c., is then briefly described; then vegetation, carnivorous habits, commensalism, &c. This is followed by sections on the distribution of Lepidoptera as affected by altitude, notes on migration, cosmopolitan species, and seasondimorphism and local variation. After this, the organic (physiological) factors of the subject are discussed, with special reference to former geological and climatic conditions, and some reference to fossil Lepidoptera. After some remarks on structure, and on the enemies of Lepidoptera, the section concludes with a summary of the Macro-lepidoptera of Central Europe (1626 species, according to Lampert), and a table of the species of Papilio found in the more important districts of the world. The second section of the work is devoted to the regions and subregions of the world as defined by Wallace, Sclater, and others, with some reference to the views of other zoologists and botanists on the subject. After this, the various regions and districts of the world are discussed, first with regard to their climatic conditions, and secondly with reference to the species of Lepidoptera known to inhabit them, of which, in many instances, very full lists are given. This portion of the work contains an enormous amount of valuable detail, and much scattered information is brought together which it would be very difficult to utilise in its original form. This portion of the work is the most extensive, but cannot here be discussed in detail. The concluding section deals with the geographical distribution of Lepidoptera under their families and genera, and this also is very completely set forth. The book is illustrated by two outline maps, one (facing p. 62) indicating the regions and subregions of the world, as mapped out by Wallace and Sclater, and the other (facing p. 217) representing the Malay Archipelago from the Nicobars and Malacca to the Philippines, New Guinea, and North Australia. Dr. Pagenstecher has not indulged in much theorising, but his book forms a great quarry from which philosophical speculators will be able to extract a vast amount of material. It is not a book that either systematic lepidopterists or philosophical naturalists can afford to ignore, and they will have reason to be very grateful to the author for the conscientious care that he has devoted to this most laborious and useful book. W. F. K. MR. HALL has again succeeded in producing a work which will appeal with equal force to the practical and to the scientific agriculturist, and will do much to overcome that innate prejudice of the ordinary practical farmer against science by showing him the enormous influence science has had in determining a rational system of manuring, and in giving him the knowledge of a variety of substances of use to him in his business of food production, as well as in securing for him a safeguard against adulteration by unscrupulous traders. In the history and evolution of the practice of keeping up the crop-producing power of the soil Mr. Hall examines critically the various theories of manuring adduced from time to time, and the experiments upon which they are based, and the study of merely this part of the work will be of supreme importance to the practical man and to the student in showing how experiments may be misconstrued and conclusions of the most erroneous description drawn. The recommendations as to the manuring of farm crops are tempered with sound advice, and the impossibility of prescribing more than a generally suitable method of manuring without a careful study of soil and climatic conditions extending over some years is well demonstrated. Mr. Hall gives some timely warnings as to deductions from field experiments, of which there has been such a plethora in recent years, with their unscientific methods both of carrying out and of deduction. The importance of taking into account the experimental error, which is estimated at 10 per cent., and of neglecting results within these limits should be taken to heart by all who carry on these so-called "experiments." The chapter on farmyard manure is eminently practical and useful, and recent work on such subjects as root excretions, effect of fertilisers on tilth, and on residual values of manures, brings the book well up to date. It is sought to distinguish between manures and fertilisers, the former designating more or less complete plant foods, the latter those materials which supply one element in the plant food, nitrogen, potash, or phosphoric acid. The perversion of the meaning of the word manure from its original significance, hand work, is no less curious than the use of the word tillage to mean artificial manures, which use still persists in the eastern Midlands. The part of the work relating to lime is worthy of serious attention from all agriculturists, as it is probable that the lack of carbonate of lime in a soil is more often than any other cause an explanation of the comparative infertility or absence of satisfactory results from manuring. A chapter on the valuation and purchase of fertilisers puts this important method of calculation simply and accurately, and a concise statement of the Fertilisers and Feeding Stuffs Act will be useful to all users of manures. Mr. Hall's remarks on the soil-inoculation question supplement and strengthen the advice he gave in his work on the soil, and the experiments on the new nitrogenous fertilisers, cyanamide and nitrate of lime, show the values of these fertilisers in terms of thei competitors, nitrate of soda and sulphate of ammonia. The Rothamsted experiments are, of course, freely drawn upon to provide data, and in the hands of the present director of that station these results are being endowed with fresh life and excellently practical applications. The tables of results are concise and wel! arranged, so that the reader is not faced with an immense array of figures and tables, and bewildered without being enlightened. To sum up, this is a sound and scientific book which should be in the hands of every practical agriculturist as well as in those of the student, the teacher, and the manufacM. J. R. D. turer. though it can hardly compare in importance with condemning a theory of teaching which no responsible some of its brilliant predecessors. pedagogical writer at least in this country-would dream of defending. Prof. Pillsbury, like his former teacher, Prof. Titchener, in a still more recent book, defines attention as 66 an increased clearness and prominence of some one idea, sensation, or object." His first thirteen chapters are devoted to the illustration of this description from general psychological processes; to an analysis of the part played by attention in the phenomena of perception and ideation, of memory, action, reason, emotion, and the self; and to a study | In addition to a good index the book contains a bibliography of the subject for which the student will be grateful. TABLES FOR MATHEMATICIANS AND PHYSICISTS. (1) Five-figure Logarithmic and other Tables. By Frank Castle. Pp. 58. (London: Macmillan and Co., Ltd., 1909.) Price IS. (2) Taschenbuch für Mathematiker und Physiker. 1 Jahrgang, 1909. By Felix Auerbach. Pp. xliv÷ 450. (Leipzig: B. G. Teubner, 1909.) Price 6 marks. sation-process or else by the nature of the objects to (1) MR. CASTLE is well known as the author of which attention is directed. There is really only one kind of attention, though the conditions of its emergence are two-fold. These are: objective conditions which consist in characteristics of the stimulus, such as its intensity, extent and duration; and subjective conditions, such as the momentary mood and past experiences of the individual. Finally, it must be noted that these conditions never or rarely appear in entire separation. The later chapters are mainly given to theories of attention, grouped as physiological theories, theories that treat attention as a phase of mental activity, and theories that seek in some particular feature or accompaniment of the attention-process the cause of the predominant "clearness" of certain sensations and ideas. As a critic of preceding theories Prof. Pillsbury's best work is his interesting and useful treatment of apperception. His own theory is a physiological one, and assumes localisation of the activity of attention in the so-called anterior association centre of Flechsig. By a kind of "drainage, for which there is experimental evidence, the discharge through a given neuronic system may be heightened by the coexistence of less energetic discharges in connected systems, or depressed by a still more energetic discharge in such a system. The association centre provides lines of irradiation along which reinforcement and inhibition may in this way spread from one sensory centre to another. By such a concept Prof. Pillsbury believes that the determination of attention, both by strong stimuli and by past experience, can be explained in accordance with the postulate of psychophysical parallelism, and without the hypothesis of an verifiable agent "that stands behind consciousness." The book ends with a chapter on pedagogical applications. The author attacks the doctrine that makes "interest the measure of what shall be taught " to a child. He argues for the use of "social pressure," and the appeal to duty in education. They are just as important as the conditions which we ordinarily call interest in governing attention, and it is quite as justifiable to make use of them in practice." This warning of a psychologist against making education "soft" is not untimely, although (owing to the lamentable ambiguity of the word "interest") he is 66 un a series of elementary text-books on mathematics. He now gives us a new set of fivefigure mathematical tables. So many tables of this sort have appeared of late years that innovation in this field is rather difficult. Mr. Castle's tables are very similar in contents to Dale's five-figure tables, with the advanced functions cut out. One hap alteration is that, in the early part of the table of logarithms, mean differences are calculated for every five entries instead of for every ten. This renders possible the use of mean differences in all parts of the table without loss of accuracy. Another good point is a table of degrees and circular functions for equal intervals of radian measure; this should be most valuable for advanced work. On the other hand, there seems a needless amount of repetition in printing. Thus the table of sines is printed separate from the table of cosines, although the one table is merely the other read backwards. The same holds of tangents and cotangents, secants and cosecants. It may be argued that this makes the tables easier to handle for readers with little theoretical knowledge, but it seems doubtful whether it will not encourage rather than check the common fault of adding, instead of subtracting, differences for the cosine, cotangent, and cosecant. A more serious defect is the omission, from the table of cube roots, of the cube roots of numbers from 100 to 1000. This means that the present tables cannot be used to find rapidly the cube root of, say, 03. (2) A pocket-book of reference for mathematicians and physicists will strike most mathematical readers, at all events in this country, as a novelty. Such a pocket-book was recently brought out in Germany by Dr. Felix Auerbach, working in collaboration with Drs. Knopf, Liebmann, and Wölffing. Facing the title-page is a portrait of Lord Kelvin, and the volume opens with a notice of his life and work. It is intended that this shall be an annual publication. For this reason, Dr. Auerbach tells us in his preface, many matters have been only lightly touched upon, or even omitted altogether, in the hope that further details concerning them may be included in a later issue. As it is, the initiated reader must be amazed at the amount of useful information which has been compressed into 450 small octavo pages. In every branch and sub-branch of mathematics all the fundamental definitions, theorems, and formulæ have been given, sufficient explanation being added to make the whole intelligible to the average mathematician. A similar plan has been adopted for the physical and astronomical parts, numerous tables of constants being given, as well as descriptions of apparatus. At the end of the book is a useful list of mathematical and physical books and periodicals. We have noticed a few errata, e.g. p. 44, the first theorem of the mean is incorrectly stated, and p. 46, An Introduction to the Science of Radio-activity. By C. W. Raffety. Pp. xii + 208. (London: Longmans, Green and Co., 1909.) Price 4s. 6d. net. THE aim of this book is to present a concise and popular account of the properties of the radio-active elements and of the theoretical conceptions which are involved in the study of radio-active phenomena. With this object in view, the treatment throughout is purely descriptive, and no attempt is made to develop the mathematical side of the subject. Nevertheless, the author has succeeded in describing and discussing most clearly the various phenomena of radio-activity. The book is divided into three parts. The first part is descriptive, and, after a general note on the radio-active elements, is devoted to the consideration of the nature of the various radiations emitted by radio-active bodies. The characteristics of the a, B, and radiations are carefully explained. The In the second part of the book the author deals with the subject of radio-active transformations, and describes in detail the various disintegration products produced from thorium, uranium, and radium. Chapter iv. in this section contains an account of the theory of atomic structure from the electron point of view. The evidence drawn from various phenomena shows large variations in the number of electrons associated in the atom. The author gives the numbers calculated from experiments on kathode rays. third part of the book is devoted to kathode, canal, and X-rays, and gives experimental details should enable an amateur to carry out successfully a number of experiments with a small amount of apparatus. A feature of the book is the appendix, in which the author has collected and tabulated the physical constants of the a, B, and y rays, the products of decay of the radio-active elements, with their rates of decay, and the absorption coefficients of the radiations emitted by the radio-active bodies. which Altogether the book can be heartily recommended to mathematical, as well as non-mathematical, readers who desire an acquaintance with the subject of radioactivity. British Mountain Climbs. By George D. Abraham. Pp. xvi+448. (London: Mills and Boon, Ltd., 1909.) Price 7s. 6d. net. MR. ABRAHAM here provides the lover of British mountaineering with a conveniently small and concise guide to the British rock-climbs. The i climbs are grouped around the most convenient centres, and detailed instructions as to how to perform the various expeditions safely are given. The book is provided with eighteen illustraprincipal routes. It is written in a bright, interesttions and twenty-one outline drawings, showing the ing style, and is sure to become a favourite among mountaineers who are willing to learn from it the beauties and difficulties of climbing at home. The Pond and other Stories. By Carl Ewald. Translated from the Danish by Alexander Teixeira de Mattos. Pp. 320. (London: Everett and Co., 1909.) Price 6s. net. THIS series of eleven stories deals with animal and plant life in a way dear to children. The birds and beasts talk to one another, and incidentally supply the reader with many familiar facts of nature-study. Each story is provided with a good illustration, and the easy colloquial English of the translator will be understood by the young children for whom the book is evidently intended. LETTERS TO THE EDITOR. [The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part of NATURE. No notice is taken of anonymous communications.] Magnetic Storms. DR. CHREE contends that magnetic observations have now reached a high pitch of perfection, and that their discussion is not lightly to be undertaken by outsiders. That is no doubt so, and there must be many features about magnetic storms which are known only to experts. But when we find experts in doubt on such a fundamental matter as whether the cause of those storms is to be found in the sun or in the earth, it appears to be worth while to emphasise some comparatively simple and fundamental considerations which may possibly have become rather covered up by a mass of information. The simple points that I venture to emphasise, with all due deference to specialists, are: (1) That by reason of the high temperature and convulsions of the sun it is almost bound to emit electric projectiles. (2) That when the visible sign of a solar eruption is aimed at the earth, magnetic storms are often felt, while they are not so frequently experienced from eruptions the emissions of which may be reasonably supposed likely to miss the earth. (3) That, taking into account the varying aspect of places on the earth to a solar beam, such a stream of particles is well qualified to produce changes in all the magnetic elements during the course of a day-even though deflection by magnetic lines, and the effect of currents induced in the conducting layer of the upper atmosphere, were ignored. (I do not say that the details of a storm fit so greatly simplified a theory.) (4) That a great beam of this kind is not likely to be uniform, but may be supposed to contain rays of special intensity, the passage of which will cause well-marked and rapid reversals, such as are observed. was (Of course, I never thought that the recent storm over in fifteen minutes; it was common knowledge that it lasted for hours. I must have expressed myself badly if I conveyed such an idea.) (5) That detection, in storm-recurrence, of any periodicity which corresponds at all closely with the period of the sun's relative axial rotation-such as is maintained by Mr. Maunder and apparently half admitted by Dr. Schuster— would surely be conclusive as to something solar in origin. (6) And, especially, that simple calculations from known laboratory data show that the magnitude of the effect observed is not unreasonably great to attribute to local solar radio-active emissions. Hesitation as to the truth of this last proposition was, |
