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THURSDAY, JANUARY 16, 1890.

THE NEW MUZZLING REGULATIONS.

N essential fault of popular government is in danger of being exemplified just now by the possibility of the selfish interests of a few individuals attracting favourable attention, in utter opposition to the true interests of the nation at large.

A very reprehensible leading article which appeared in the Standard on the 4th inst., to which we shall presently refer in fuller detail, has started an agitation in the home counties, especially in Kent, in opposition to the valuable regulations recently issued by Mr. Chaplin against hydrophobia or rabies.

It is not uninstructive to review the way in which the issue of these regulations has been brought about, while is a matter of painful interest to compare our position in England, as regards the prevalence of rabies, with that of some of the more advanced nations on the Continent. Before M. Pasteur began his wonderful researches into rabies, the vast majority, even of the highly instructed public, regarded hydrophobia as a kind of Divine visita*ion, and rabies as a form of canine lunacy. Legislation, in the absence of that which has so frequently been called with a double meaning "a healthy despotism," necessarily agged behind in the arrest of what everyone now knows to be a simple zymotic disease, which, enzootic in Engjand, becomes, by steady increase during every few years of unchecked development, both epizootic and unfortuately epidemic.

The first advance towards rational prevention of the trouble was made in London in 1885-86 by the Chief Commissioner of Police, first by Sir E. Henderson, afterwards by Sir Charles Warren.

The result of their work is well known-namely, the temporary extirpation of rabies in London. In a country with more respect for scientific fact, such a benefit to the mmunity would have been followed by the general eablishment of preventive legislation throughout the entres of the disease, so as to arrest it completely; and the having been effected, the adoption of proper quaranLine measures would alone of course have been required to free us for ever from the evil by preventing its reintroduction from abroad.

Partly owing to the fact that, until the most wise estabchment by the present Government of a General Board of Agriculture, there was no special authority for moving in the matter, no such general action was taken. Lord Cranbrook, however, was earnestly convinced of the importance of the subject, and conferred a lasting benefit on all those interested in it by appointing that Select Commutter of the House of Lords whose Report and evidence not only furnished a complete and exhaustive account of rabies, but also strongly emphasized the necessity of the adoption of thorough legislative measures, especially of muzzling, to prevent and eradicate the malady.

In the meanwhile, rabies in dogs, and of course concurrently its fatal attacks on men, steadily increased, until the spring of last year (1889) saw us threatened again in London with an epidemic like that of 1885.

enced the manifest value of the regulations of 1885 called for the reinstitution of the muzzle, and at the present time the Field, Fancier's Gazette, &c., afford strong proof, in the earnestness of their expressions of satisfaction at the present muzzling order, of the folly of their contemporary who has endeavoured to oppose it.

Of course, as before, a few agitators, trading on the innate selfishness of some natures, and supported by the money of a small band of individuals whose names should be for ever preserved as having sought to work harm to their fellow-creatures, recommenced their irresponsible attacks on the authorities and others for this much-needed sanitary regulation, and it is a recrudescence of this selfish obstruction which the Standard has attempted for some (as yet unknown) reason to revive.

An amusing, if degrading feature of such opposition is the constant change of front which the inevitable progress of scientific truth forces upon these people, as their misstatements and ignorance become revealed to the public. At different stages of the agitation, their leaders, Miss Cobbe, "Ouida," and others, have stated with inexplicable self-contradiction, that no such disease as rabies existed, that it was wholly imaginary, that it was rare in England, that the police ran no risks in extirpating it, that the muzzle produced this (non-existent) disease, and so on to the end of the chapter. But while the logical difficulties in which these writers involve themselves must excite amusement, it is a matter of serious regret that they cannot be legally dealt with like other disseminators of false news, such for instance as those who in the wilderness of the "great gooseberry season" cry "'orrible murder" when homicide is pro tem. non-existent. The evil done by these latter is indeed small, compared with that of the far graver false statements which we have cited above.

In spite, however, of this flood of misrepresentations the muzzling regulations were enforced in London, and with notable benefit, and by the recent order they have been continued and extended by Mr. Chaplin, so as to cut right at the root of the evil, viz. in all the centres of the disease simultaneously.

It was with the consciousness that this measure would be required by the country of the President of the Board of Agriculture, that the anti-muzzlites made a last effort against it by holding a public meeting. The real nature of this agitation, which had been notorious from the commencement, was then made most amusingly conspicuous. We refer to the fact that this variety of obstruction is in truth only a branch of the anti-vivisectionist agitation, and worthy of such a parent stem. It seems that at the meeting an amendment in strong support of muzzling was carried by a majority of something like 80 per cent. The fact of the origin of the Association which had summoned the meeting having been alluded to, the Chairman, the Bishop of Ely, first (we are glad to see) repudiated the idea that he was an anti-vivisectionist, and then went on to say that the anti-vivisectionists had nothing to do with the anti-muzzling agitation. This repudiation on the Bishop's part was followed by the resignation of the originators of the movement, Miss Cobbe and others, demonstrating the truth of what we have just said and the inaccuracy of the Bishop's second statement.

The general facts bearing upon the origin and develop

All the large dog-owners and breeders who had experi- ment of the agitation were fully exposed at the meeting, VOL. XLI.-No. 1055.

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institutes. Its official name ("Trustees of the City Parochial Charities ") is unfortunate; it has too much of a flavour of Mr. Bumble's "porochial" office. It would require an Act of Parliament to change the name, so the best thing to do is to let it be forgotten. The Central Governing Body (for so let us call it) is to be representative of the Crown, the City Corporation, the County Council, the higher Colleges and University of London, the Ecclesiastical Commissioners (temporarily), and the Governing Bodies of the Bishopsgate and Cripplegate Foundations. No one can forecast the action of such a hybrid body until we know the actual men who are to be nominated. A very efficient educational body might be elected as proposed, and on the other hand it mightn't. It is to be hoped that one of the blots on the constitution of the Board-the absence of working-men representativeswill be partly corrected by the inclusion of some workingmen leaders among the five Crown nominees. But it is impossible to resist the conviction that the suggested constitution suitable enough to the time when the Act was passed and London had no organized system of local government has far too little of the popular element, and that it would be far better to put the whole management of the scheme in the hands of the County Council, or a joint committee of the County Council and School Board.

Supposing that the Central Body is all that could be wished, the next thing to ensure is the satisfactory composition of the governing bodies of the various institutes, and their organic connection with the Central Body. It is essential that the schemes shall be so arranged that the educational programme of all the institutes shall pass through the hands of competent experts, and the educational work shall be adequately supervised, inspected, and revised, from time to time. The Charity Commissioners propose two methods of attaining this result. They give three nominations on each governing Board to the Central Governing Body, and these three members may be experts, though of this there is no guarantee. Further, the secretary of each institute is required to send to the secretary of the Central Governing Body a complete list of proposed classes a week before each term. This is presumably intended to give a power of suggestion, if not revision, to the Central Body, but what is the use of suggestions a week before term? What is wanted is a central committee of well-known experts to advise the Central Governing Body on educational matters. The committee should be small-say three scientific and three artistic representatives. They should be paid for their services, and should be in touch with the science and art divisions of every institute.

There is nothing in the scheme to prevent the appointment of such a Committee, though it would be well if some distinct suggestion of the kind were made. In any case it is a matter to be borne in mind and pressed when the time comes, for it may make all the difference in the world to the future of technical education in London. Let us be frank about the matter. How many men are likely in any given district to be on the governing body of the local institute who know the difference between good teaching and bad? And yet no scheme, however admirably drawn, will produce a good technical school, unless it is worked by such men. On the other hand,

with a first-rate governing body we have little fear. Payment by results will lose most of its terrors if those in power know the difference between the incompetence which cannot earn grants, and the independence which prefers real teaching to cram. And we may add that it is only by associating with the governing body members. engaged in local industries that the practical character of the trade classes can be assured.

So much for the machinery. We must next say a word about the character of the instruction to be aimed at in the institutions. It is to be mainly technical, and hence must be adapted to the special needs of each locality. It is by this time a truism to say that this adaptation will not be brought about by allowing a set of science and art teachers to take the line of least resistance through the South Kensington Directory to the goal of the maximum of grant. A lady is reported to have lately obtained a silver medal for agriculture at a London institution which the Charity Commissioners are proposing to endow. Is this adaptation to local needs and industries?

We wish sincerely that those responsible for the whole scheme had been able to arrange for exceptional treat ment of the new [institutes in the matter of the apportionment of the Government grant now paid on resultNo better opportunity is likely to present itself for an experiment in basing grant on efficient inspection rathe than on examination. But what chance is there of such a proposal when our Government departments responsible for public education are cut up into air-tight compartments without connection among themselves? The Charity Commission, the Education Department, and the Science and Art Department still form a great circumlocution office. and until this is altered abuses will continue, which it nobody's business to remedy. Our great hope, therefore, de pends on the choice of the principals, teachers, secretaries inspectors, and governing bodies, who will make or m the institutes through which, for many years, Londoners will derive their technical instruction. Let them be er lightened men, with broad views and sympathies, who know their business, or at least know their limitations. and all may be well. But if not, it were better that the whole scheme were put in the fire.

What, again, is to be the scope of the instruction? Is t to be mainly confined to the level of "elementary" scienc and "second-grade" art? Or are there to be advances classes in more specialized subjects? Provision is mad for such classes in the scheme if they can be arranged without trenching on the endowment. The Comme missioners are probably afraid of misapplying funds intended for the poor to the benefit of the middle class There is justice in their objection, but such instructor can never be made self-supporting, and it is most i portant that it should be included in the programmes the institutes, if only to keep the standard high througho Here is then an opportunity for the City and Guid Institute. Let it relieve itself of the charge of its examrur? tions, which may now be transferred on equitable terms to the Science and Art Department under the provisions the Technical Instruction Act, and let it also transfer to the Government the Central Institution, the geographical situation of which marks it out plainly as an adjunc rather than a rival to the Normal School, and let it app the energy thus liberated in establishing in every " Pow

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technic "a higher department, providing for the more specialized wants of each locality. This will be a work which no body is so well fitted to undertake as the great Institute which has been a pioneer in higher technical instruction. Such, it appears to us, is the true solution of the question of the relations between the Charity Commissioners' scheme and the City and Guilds of London. One word of caution in conclusion. The new institutes should be allowed to grow, and not be started on too ambitious a scale at first. Local wants change, and the institutes should develop in harmony with their changes. This is the lesson of the old Mechanics' Institutes and Athenæums. The lesson is repeated in the newer experiments of Mr. Hogg's Polytechnic, and the People's Palace. We do not want to begin with erecting huge shells of bricks and mortar, hoping that life will somehow come into them after a time. The life first, then the buildings, to grow as it expands and deepens that surely is the law of nature. "Several architectural white elephants" is the dismal but suggestive forecast of a writer in the Charity Organization Review, on the supposition that this law is violated. If these warnings are neglected, the promoters of the movement will be merely courting failure, however good their intentions may be. And they will have failed because "they were not poets enough to understand that life develops from within."

ASSAYING.

well calculated to give trustworthy indications as to the quantity and quality of metal obtainable from ores. These are to be found in well proved "wet" methods of determining actual copper contained in ores as well as the components that interfere with the extraction and the quality of the metal. In describing these methods, ample information is given for the guidance of the smelter under the varying conditions of the metal's occurrence. While passing shortly over the Cornish assay, the authors judiciously omit such clumsy "wet" methods of assay as the direct titration by cyanide of potassium, which is retained in some recent books of standing, although it has been abandoned by most skilful assayers. On the other hand, titration by cyanide of potassium after separation of the copper from interfering metals, and the assay by electrolysis, leave little to be desired in rapidity and accuracy, and to these due prominence is given. Failing reasonable manipulative skill, no assay can be accurate, and the expertness demanded by those who conduct the dry" or Cornish assay is not more easily acquired than is the analytical skill needed for better "wet" methods. In an assay method giving accurately the amount of metal actually present in the ore, the metallurgist has a sure basis for calculation, the results of which can be brought under the control of his experience as to the losses of metal in operations on a large scale. The results of the Cornish assay, with all its inherent uncertainty, have equally to be judged in the light of the smelter's experience as to what the final “out-turn " will be. In lead, again,

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Text-book of Assaying. By C. Beringer and J. J. Beringer. the dry assay is usually treated in books on assaying with (London: Griffin and Co., 1889.)

THIS HIS text-book marks an important departure in the literature of assaying. The authors abandon the dreary details of traditionary methods, and attempt with success to rationalize the art of the assayer, rather than to follow the usual course of reproducing "dry" assay methods and elaborate classifications of processes the interest of which is only historical. Assaying is here treated, in a broad sense, as the determination, by analytical methods, of components of ores and of intermediate or finished metallurgical products. Such compounds may be either of value in themselves, or important from being valuable or injurious in the operations of smelting, or in adapting the metals for use.

The methods of the authors, and the measure of success which they have attained, may be fairly judged by their treatment of copper, ead, and iron. Copper ores and furnace materials are still sold in the English market by the "Cornish" assay. This antiquated method of assaying has really no claim to retention, now that more trustworthy methods are well known, and the authors give it but little prominence. They, however, repeat the fallacious argument of its apologists by stating that "it gives the purchaser an idea of the quantity and quality of the metal that can be got by smelting." The Cornish assay does not deserve even this modified approval, as the results it affords neither represent the actual amount of copper contained in the ore, nor the proportion of metal which can be produced by smelting, and several expert assayers, working on portions of the same samples, will obtain results which vary in the most erratic way. Fortunately for those who may be guided by this text-book, its authors proceed to describe assaying processes which are really

much elaboration, which is no longer useful, if it ever was. It gives results that indicate neither the actual amount of metal contained in the ore, nor the amount which will be produced by smelting, and like the Cornish assay for copper is most unsatisfactory for guidance in smelting. The wet methods of lead assaying which are described are convenient and trustworthy, while the only practically useful methods of dry lead assay are given in sufficient detail. In the assay of iron ores we find dry methods entirely omitted. The wisdom of this cannot be doubted, for the want of exactitude which is characteristic of the dry assay of copper and lead is still more marked in the dry assay of iron. Processes of wet assay capable of giving prompt and strictly accurate results are available, and these are fully described.

The plan of subordinating or ignoring unsatisfactory methods of assay, while giving prominence to those which have proved to be trustworthy, runs through the treatment of methods of assaying the other metals, as well as estimating the components of ores which are not usually dealt with in books on assaying. Among the latter are silica, the earths, sulphur, arsenic, and phosphorus. These demand study by the metallurgist, to whom, under either the necessity of "fluxing" them away, or of minimizing their interference with the purity of the metals, their ready and accurate determination is a matter of the greatest importance. The details of assaying the precious metals, though hardly sufficient for adoption in the assay of bullion in a mint, are all that is needed in a works.

The authors have clearly not been content to merely record published processes, but in order to add to the completeness of their work have given unpublished

results of the experience acquired by themselves and others. The writer notices their description of a process for the estimation of arsenic in minerals and metals, which was devised by himself for use in works under his control, that has not hitherto been published. It consists in the separation of arsenic from its associations, by distillation with ferric chloride mixed with calcium chloride, and subsequent titration of the distillate by iodine. The authors are mistaken in stating that there is a difficulty in obtaining ferric chloride free from arsenic. Even if there were difficulties, it is obvious that the process itself affords a ready means of eliminating arsenic from the ferric chloride mixture, before using it in the actual assay. In this and one or two other cases, there is a tendency to adopt the always undesirable method of "blank" experiments to correct error arising from the use of impure reagents, rather than whenever practicable to avoid the source of danger by the use of pure materials. These are, however, hardly noticeable blemishes in a really meritorious work, that may safely be depended upon by those using it either for systematic instruction or for reference. THOMAS GIRB.

BREWING MICROSCOPY.

The Microscope in the Brewery and Malt House. By Chas. Geo. Mathews, F.C.S., F.I.C., &c., and Francis Edw. Lott, F.I.C., A. R.S.M., &c. (London and Derby: Bemrose and Sons, 1889.)

THE

HERE are certainly few industries the growth and development of which have been more influenced by the progress of pure scientific discovery than those of the brewer and distiller. These industries, formerly carried on upon purely empirical lines, handed down from father to son through countless generations, have in recent years, through the advances in chemical and biological science, been so transformed that their successful conduct at the present time requires a most thorough acquaintance with the leading principles of these sciences. As a consequence of this change, we find an increasing tendency for these industries to become concentrated in a smaller number of hands each producing on a larger and larger scale. The small brewer himself lacking the necessary scientific training, and not able to afford the requisite skilled assistance, gives way before the larger breweries employing a complete scientific staff and provided with the latest improvements.

The present work is, we understand, intended to bring before those connected with brewing a concise account of the assistance which may be derived in the conduct of their business from the use of the microscope. We are of opinion that the authors have been unfortunate already in the choice of their title, as one of the most conspicuous results of modern scientific research in this direction is that the use of the microscope alone is of comparatively little value in the study of micro-organisms in general, whether connected with fermentation or other processes. This inadequacy of microscopic study per se the authors in various parts of their work indeed frankly admit. Modern students of these low forms of life have, in fact, become

more and more aware of the fallacious results yielded by mere microscopical observation when unaccompanied and uncontrolled by those processes of cultivation which have been developed during the past ten years. Even the work performed under the auspices of the masterly genius and supreme experimental skill of Pasteur has had to be revised and brought up to date by Hansen, with the aid of the more recent methods of research. Now, although the authors appear fully aware of the great change which has taken place since the earlier work of Pasteur, Reess, Fitz, and others, they have not sufficiently distinguished between observations which rest upon the surest founda tion and fulfilling the most modern requirements, and those which, though possibly correct, require repetition and confirmation.

The absence of sharp differentiation in this matter cannot fail, we believe, to occasion much confusion in the mind of the ordinary practical student who depends upon text-books and manuals for his guidance and information, and it is, in our opinion, quite unnecessary that he should be burdened with the microscopic de scriptions of the various forms of yeast given by the older observers, who were almost certainly dealing with impure cultures, but on the contrary he should rather devote his whole attention to the characters of such undoubtedly pre forms of yeast as have been obtained by the most recent methods. Moreover, unless the necessity of resorting these cultivation experiments for obtaining accurate information is duly impressed upon the student, he will ¦ naturally be inclined to shirk these far more laborio. and difficult observations, and place undue reliance upon microscopic features.

These remarks apply, perhaps, with even greater forcet › the manner in which the authors have dealt with the schizomycetes; in this part of the book we find much space devoted to microscopic descriptions of bacteria of uncertain purity, whilst there is little or nothing sad about the methods by which these organisms can be really identified, and their characters defined. We als miss any adequate account of the staining-processes which are so invaluable in obtaining a correct idea of the microscopic forms and dimensions of bacteria. As an instance of the unsatisfactory present condition of brew. ing microscopy, we may quote the following sentence “Bact. lactis, as seen in beers, is generally in the form of small rods, 2 to 3 μ in length, and sometimes in threads containing from 2 to 5 individuals; it is not certain. however, that this form is B. lactis." Thus, in respect of the bacterium which is perhaps of most consequence to the brewer, as being "the most commonly occurring disease-organism encountered in the brewing process there is this absolute lack of all precise information.

What may be called the more purely scientific part of the work is succeeded by a chapter of "general remarks on the brewing process," which, embodying as it de some of the practical experience of the authors themselves, we would have gladly seen enlarged.

The book, which is printed on excellent paper and elegantly got up, is illustrated with a number of admiably executed plates, many of the best of which are original.

A full index and glossary are appended.

OUR BOOK SHELF.

By Robert (London:

Flower-Land: : an Introduction to Botany. Fisher, M.A., Vicar of Sewerby, Yorks. Bemrose and Sons, 1889.) THIS is a capital first book of botany, intended for small children. The style, however, is really more elementary than the matter, and a child who has mastered this book will have made a very good start in the science. There is a good deal of information given about the internal structure and function, as well as the external form, of the organs of plants, and this information is given correctly, as well as clearly.

The book is illustrated by 177 woodcuts, most of which are well suited to their purpose. D. H. S. Fee Months' Fine Weather in Canada, Western U.S., and Mexico, By Mrs. E. H. Carbutt. (London: Sampson Low and Co., 1889.)

Ix this book Mrs. Carbutt records her experiences during remarkably pleasant journey made by herself and her husband in the New World. The scenes she describes have often been described before, but she writes so brightly thout what she saw that even readers to whom she has nothing new to tell will find a good deal to interest them in her narrative. They will be particularly pleased with her account of " sunny Mexico, and its merry, courteous people."

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.]

The Duke of Argyll and the Neo-Darwinians. It has a curious and not uninstructive effect to see the rges of this journal invaded by the methods of discussion orch are characteristic of political warfare. The letter of the Duke of Argyll, published in NATURE for December 26, 1889 (173) is a clever debating speech. But it rather obscures than dommates the questions really at issue. And, after the fashion of the political orator, it attributes to those who disagree with t' writer motives which, in so far as they differ from reasoned conviction, are essentially insincere.

In politics, the personal rivalry which is bound up inextricably with the solution of great problems may make it a necessary part of the game to endeavour to belittle one's opponents. But in-cience it is not so. The newer problems which have been rased by Darwinism depend for their solution upon the discussion of evidence, and no competent biologists will, in the long run, be influenced in the opinions they form about them by anything

else.

There is nothing in the Duke's letter which has not been worn threadbare by discussion. Still, there are, no doubt, many readers of NATURE who, while taking a general interest in the maiter, have not followed all that has been written about it. I am disposed to think, therefore, that it may not be without its use to go over the ground which the letter covers.

First, as to acquired characters. Let us take a simple case. It is admitted that a blacksmith, by the constant use of his arms, may stimulate their abnormal muscular development; that is an acquired character. But a working man, whose arms are of perfestly average dimensions, may nevertheless have a son with arms which would seem to mark him out for the blacksmith's profession; that would be a congenital variation. Now we know that a congenital variation is likely to be inherited; that is a matter of observation. What is the case as to the acquired character? The answer must be, I take it, that there is no probability that the arms of a blacksmith's son will differ in any respect from those of the average inhabitant in the locality where he was born. The Duke of Argyll, however, suggests that there "no necessary antagonism between congenital variation and the transmission of acquired characters." This is perfectly

reasonable; theoretically, there is none. But this does not make the transmission of acquired characters less doubtful. The Duke has no doubt about it, however. "So far from its being unproved, it is consistent with all observation and all experience. It lies at the foundation of all organic development. Very possibly, but where is the observation and where is the experience? These are the biological desiderata of the day. Imagine the fate at the Duke's hands of any scientific writer who put forward statements such as these unsupported by a shred of a fact.

"This being so," however, the question then arises, Why do extreme Darwinians so fiercely oppose the idea of the transmission of acquired characters? Well, it is obvious that they do so because they think the evidence in its favour insufficient, and it is clearly the duty of a scientific man, whether an extreme Darwinian or not, to oppose the acceptance of that which experience does not support. But the Duke of Argyll attributes their opposition to two causes: first, jealousy of associating the names of Lamarck and Darwin; and, secondly, the dethronement of their idol Fortuity. The first of these reasons is almost too preposterous to discuss. No serious naturalist would speak with other than respect of Lamarck's position in scientific history; this cannot be effaced however much that of Darwin may be magnified. And no serious naturalist would adhere to any theory Darwin had propounded a moment longer than the evidence seemed to carry conviction. The charge in this particular matter is, however, the more grotesque, because, although Darwin did not esteem as of much value Lamarck's doctrine of development and progression, we know that his own mind became more and more fluid on the question of the "direct action of conditions." The idea is in fact so plausible that the difficulty is not in accepting it, but in shaking oneself free from

it. What were probably the last words which Darwin wrote on the subject are contained in a letter to Prof. Semper, dated July 19, 1881. I quote a passage which appears to me to pretty accurately define the present position of the question :"No doubt I originally attributed too little weight to the direct action of conditions, but Hoffmann's paper has staggered me. Perhaps hundreds of generations of exposure are necessary. It is a most perplexing subject. I wish I was not so old, and had Hoffmann more strength, for I see lines of research to follow. even doubts whether plants vary more under cultivation than in their native home and under their natural conditions ("Life and Letters, vol. iii. p. 345).

Darwin's difficulty, in point of fact, was exactly that of everyone else. The evidence, instead of being "consistent with all observation and all experience," failed to be forthcoming..

The second reason is equally baseless. Fortuity is no idol of the neo-Darwinians; if it is an idol at all, it is an "idol of the market," imposed upon their understanding by the Duke. But And as

at any rate he does not attribute any blame to Darwin. this is a rather important matter, on which I admit that persons who ought to know better have gone astray, I will quote a passage on the subject from Prof. Huxley's admirable biography (Proc. Roy. Soc., No. 269) :—

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"Those, again, who compare the operation of the natural causes which bring about variation and selection with what they are pleased to call chance,' can hardly have read the opening paragraph of the fifth chapter of the Origin' (ed. 1, p. 131): I have sometimes spoken as if the variations had been due to chance. This is of course a wholly incorrect expression, but it seems to acknowledge plainly our ignorance of the cause of each particular variation.'

It is obvious that the use of accidental in the guarded sense in which it is employed by Darwin is widely different from fortuitous as employed by the Duke of Argyll. Darwin took variation as a fact of experience. Its causes and laws have still to be worked out. One of the latter, due to Quetelet, was explained by Prof. George Darwin in this journal (vol. viii., 1873, p. 505). He says: "One may assume, with come confidence, that under normal conditions, the variation of any organ in the same species may be symmetrically grouped about a centre of greatest density.

And this is quite in accord with the remark of Weismann that variability is not something independent of and in some way added to the organism, but is a mere expression for the fluctuations in its type. Variation is therefore not unlimited, and we must admit with Weismann that its limits are determined by "the underlying physical nature of the organism;" or as he again puts it, "under the most favourable circumstances a bird

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