THURSDAY, NOVEMBER 10, 1892.

EXPERIMENTAL BIOLOGY. Experimental Evolution. By Henry de Varigny, D.Sc. (London: Macmillan, 1892.)

DR.

R. HENRY DE VARIGNY has enriched the literature of biology by publishing in the "Nature Series the lectures on Experimental Evolution " delivered by him in 1891 to the Summer School of Art and Science in Edinburgh. This school, as is well known, I has been doing good work on Extension lines in Edinburgh, and Prof. Geddes is to be congratulated on having secured the co-operation of so able a biologist and so lucid an exponent of the special aspects of biology with which he has identified himself as M. de Varigny. The lectures are well worthy of publication, for they contain a rich, well-ordered, and, for the most part, well-sifted body of facts collected from many sources, and especially E from the publications of French naturalists. But the author is more than a collector of facts recorded by other workers; he is himself a worker in this special field of biological science. And some of the most valuable of the observations contained in the work are the result of his own careful and exact investigations.

Experimental biology is still in its infancy. It is true that our domesticated animals and plants are the result of much experimental work in the past; but the experiments were not planned with the object of explaining organic nature, and were therefore not biological in their aim. There is pressing need at the present time for experiments with such definite scientific aim; for experiments, that is to say, carried out with the express object of testing the truth of biological principles. And that this work be well done there is pressing need for organization. We have only to look at the results which have been reached by well-planned and well-directed marine stations in extending our biological knowledge, faunal, morphological, and embryological, to see what may be done by organization of research. What Dr. de Varigny eloquently pleads for, and what our own countryman, Dr. Romanes, is also pleading for, is an experimental institute, well planned and adequately supported, the purpose of which shall be to carry out extensive experiments for testing evolution hypotheses in all their bearings.

"It appears to me," says Dr. de Varigny, "that this institution should comprise the following essential elements-Rather extensive grounds, a farm with men experienced in breeding, agriculture, and horticulture; some greenhouses, and a laboratory with the common appliances of chemistry, physiology, and histology. Of course this must be located in the country. It is very important to have experienced farm hands, and a good chemist and histologist are necessary in the staff of the institution. As to the general management, it seems advisable to have a director with a board of competent men, whose functions would be to decide, after careful nvestigation and exchange of views, what are the fundanental experiments to be performed. These experinents, when once decided upon, should be pursued

during a long period of years, and nothing should be altered in their execution unless considered advisable by the board, or unless the experiment should be found useless, or devoid of chance of success. The main thing should be to provide for the duration of the experiment, whether the originators were living or dead, and to follow it out for a long time. Time is an indispensable element in such investigations, and experiments of this sort will surely exceed the normal duration of human lifetime.”

A special branch of the work of such an institute should be experimental investigations in comparative psychology. Of this there is nowadays some need. Speaking of the transmission of acquired characters, Dr. de Varigny says, "Psychology affords similar instances. A kitten which has never seen a dog is afraid from the first moment it perceives one; young birds of many species instinctively fear the hawk and other birds of prey, while remaining unaffected by the presence of other birds. Are not these psychological attitudes' due to environment (acting on the mens of ancestors) which have been transmitted by inheritance; are these not acquired characters?" From observations of my own I am prepared to say that it is by no means universally true that a kitten which has never seen a dog is afraid from the first moment it perceives one. Mr. Spalding does indeed describe how the smell of his hand with which he had been fondling a dog set four blind kittens puffing and spitting in a most comical fashion. But a careful observer, Mr. Mann Jones, writes to me that a young kitten with which he experimented took eight days to connect the smell or odour of his hand with the thing-dog." And my own observations are confirmatory of those of Mr. Mann Jones. Mr. Hudson, in a very interesting chapter of the " Naturalist in La Plata," gives observations which tend to show that young birds afford little evidence of instinctive fear of particular enemies; and my own experiments with young chicks lead me to believe that they have no instinctive knowledge of the things of this world. Any unusual and sharp sound (e.g., a chord on the violin), any large approaching object (e.g., a ball rolled towards them), causes alarm. There is no evidence of instinctive particularization of alarming objects. Such observations lead me to look with suspicion on any arguments for the transmission of acquired characters based on supposed instinctive knowledge of things. And they show the need of further research in comparative psychology such as could be carried out at the Institute of Experimental Biology.

It may be said that the central hypothesis of modern evolution, that of natural selection, stands in no need of experimental verification. But it will presumably be admitted, even by those who are firm in their belief, among whom I count myself, that further experimental support will be of the utmost value. There are many who assume a sceptical attitude, and who say-We grant the inexorable logic of your conclusions if your premisses be established. More individuals are born than can or do survive; the devil devours the hindmost; and a beneficent selection rewards the survivors with the privilege of procreation hence, progress towards increased adaptation. A very pretty piece of logic. But now, they say, show us the devil at work. We pretend to no particular knowledge

of these matters, but we are quite ready to be convinced by proven facts. Prove to us this devil's work, and we acquiesce in your conclusion. But do not put us off with a logical "must be," the recognized symbol of an assumption. Do not tell us that since a hundred were born and only two survive, the ninety-eight must be in some way and for some reason unfit. This is just the very fact of which we require definite and indubitable evidence.

Now what solid and umimpeachable body of evidence have we wherewith to conclusively refute this scepticism? If animals or plants removed to a new environment assume a new habit, in how many cases is it clearly proved that this is due to the elimination of all those who failed to vary in the direction of this habit? It behoves us to be careful that the very strength of the natural selection hypothesis be not a source of weakness, by leading us to neglect the duty of experimental verification. That there should be a central institute or institutes for the purpose of such experimental verification, is what Dr. de Varigny and Dr. Romanes are pleading for. It would produce a salutary organization of research; for the institute would have carefully selected correspondents in all parts of the world who would carry out their experiments in concert. It would bring scattered energies to a focus. It would by its journal show individual workers where research is specially needed. It is bound to come sooner or later. We hope to see it an established fact before the close of the present century. C. LL. M.

BRITISH FUNGUS FLORA. British Fungus-Flora, a Classified Text-Book of Mycology. By George Massee. In 3 vols. Vol. I. (London and New York: George Bell and Sons, 1892.)

T was in 1836 that Berkeley published his "British Fungi" as a part of Hooker's" British Flora," and for about a quarter of a century this was the standard work. In 1860 appeared Berkeley's "Outlines of British Fungology," which from the first was disappointing, inasmuch as it was only a barren catalogue for all except the large and conspicuous species; and even the latter were so compressed in description, by the exigencies of confining the book within narrow and definite limits, that it did not wholly supersede the use of the old "British Fungi." In 1871 an effort was made to repair the error by the publication of Cooke's "Handbook of British Fungi," which brought the whole subject up to date, and gave a new impetus to British mycology. On account of the considerable acquisition of species, new to the British flora, it was deemed fitting in 1871 to produce a new work which should include these additions, and then Stevenson's "British Fungi" appeared. This new work only included the "Hymenomycetes," or, in effect, part of the first volume of Cooke's "Handbook," leaving all the rest untouched. In order to remedy this deficiency in part, Cooke's" Myxomycetes" was issued in 1877, and Phillips "Manual of British Discomycetes" in 1887. Meanwhile a second edition of a portion of Cooke's "Handbook" was being issued as a supplement to Grevillea," but confined exclusively to the Agaricini. With the exception of Plowright's "British Uredinea" published in 1889, all the rest of the orders contained in

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the "Handbook" remained as they were in 1871. The unrevised portions included the Pyrenomycetes, or Sphæriaceous fungi; the Sphæropsidea, or imperfect Pyrenomycetes; and the Hyphomycetes, or moulds. Hence the announcement of a complete work which should include all the British fungi, of whatever denomination. brought up to date, did not come as a surprise.

The volume before us consists of 430 pages, and professes to be the first of three volumes, which are to contain the whole "British Fungus Flora" in full, and upoz the same plan as this first volume. We have heard of wonderful feats of "strong men," but these will be nothing in comparison to the feat which is ostensibly promised on the title-page, when it is accomplished. our simplicity we should have calculated six volumes as nearer the minimum. If the result proves to be less, we shall be content to bear the odium of a false prophet We may premise that the author who has undertaken the present work is eminently fitted to carry it out success fully, inasmuch as he is a practical field naturalist, with independent views, and by no means afraid of hard work To return to the volume in question, we must recognize clearness of typography, and distinctness in the isolation of species, which will facilitate reference and increase its practical utility. The illustrations are rather rough out lines, but quite sufficient for practical purposes, and wil exhibit the distinctions between the several genera as fa as illustrations can do it. Of the systematic arrangemen we are not prepared to speak so highly, but perhaps som may consider this a matter of detail. The contents may be summarized thus, in the order of their appearance The Gastromycetes, or puff-ball fungi, commencing with the subterranean species, followed by the Sclerodermed and the Nidulariea, then the Lycoperdea, concluding with the Phalloidea. These are succeeded by the Hymen mycetes, in like manner inverted, commencing with th Tremellinea, and backwards through the other families t the Agaricini, which are commenced in the last 12 pages, but not half completed. We imagine that ha another volume will be required to complete the Basidio mycetes.

Under ordinary circumstances, when we take up a flora, we are accustomed to meet with the adoption o either one of two methods. The one consists of a regula sequence, from what the author regards as the highes developments in his congeries to the lowest ; the other a equally regular sequence from the lowest to the highest This is conventional, but the present book is not conver tional. In one sense there undoubtedly is a regul sequence from the lowest forms to the highest in the Basidiomycetes, which this volume contains; but we mus not infer that Mr. Massee regards the Basidiomycetes as the lowest order of Fungi, or that he commences with the simplest organisms, proceeding upwards by regula gradations to the most complex, when he starts with the Gastromycetes. Undoubtedly our author has not mad a special study of the puff balls in order to degrade the to the lowest rank. Hence we can only arrive at ors conclusion, and that is, that such portions of the wors have now been printed as were ready for the press, and no conclusions are to be drawn from the sequence adopted as a convenience, as if it were adopted by pre meditation.

Continental mycologists have now for some time accepted the genera of the Agaricini as defined by Fries, with the exception of the large genus Agaricus, which Fries himself subdivided into numerous smaller groups as subgenera; but they have elevated all these smaller groups to the rank of genera, and placed them upon an equality with the other veritable genera of Agaricini. Against this metamorphosis we feel bound to contend, on the ground that the distinctions, although sufficient for the subdivision of a genus, are not of generic value, and that the genera so constituted are unnecessary, and of unequal value, with the old genera beside which they are placed. For instance, Amanitopsis differs only from Amanita in the absence of a ring; and Annellaria differs only from Panæolus in the presence of a ring. Let any one of practice and experience compare these pseudo-genera with Coprinus, Cantharellus, or Schizophyllum, and judge of what we say. For the first time these pseudo-genera now find a place in a British flora, and, although not of overwhelming importance, we cannot permit them to pass without protest.

Spore measurements are a recent addition to the diagnoses of Hymenomycetes, and, although we contend. that they should be employed with caution and discrimination, it is very satisfactory that so much attention should have been given to them in this work. Not only does the spore vary in size in a given species in different seasons, but at different periods in the same year. This is certainly true in some species which have been tested, and should lead us to accept spore measurements as approximate rather than absolute.

In conclusion, we are bound to remark that this is a student's book, written with a full appreciation of the wants of a student, and giving all the information which a student might require. In all cases, whether under families, genera, or species, will be found just the details which the novice will be most anxious to obtain, and, although the study of these interesting but rather difficult plants has been of late somewhat upon the decline, we doubt not that it will revive and prosper by the aid of the new "British Fungus Flora," which will become the "text-book of British mycology." M. C. C.

SOUTH AFRICAN SHELLS. Marine Shells of South Africa: A Catalogue of all the Known Species, with References to Figures in Various Works, Descriptions of New Species, and Figures of such as are new, little known, or hitherto unfigured. By G. B. Sowerby, F.L.S., F.Z.S. Pp. 89, 5 pls. [drawn by the author]. (London, 1892.)

SIN

INCE 1848, when Krauss published his well-known work, entitled "Die Südafrikanischen Mollusken," no such list as the one before us dealing with the Molluscan Fauna of this interesting and important marine province has appeared.

Krauss, who included the non-marine forms of the South African region in his work, recorded 403 marine species, of which 213 were considered to be peculiar to the province. Many other species have been subsequently cited or described as coming from that quarter, notably by E. von Martens and by our present author. Conchologists undoubtedly owe much to Mr. Sowerby

for thus bringing together within the small compass of this single volume, the scope and aim of which are sufficiently indicated in its title, the scattered records of the various species as known to him; but they will equally regret that the author did not include the whole molluscan fauna instead of confining himself to the testaceous forms, and thereby raise the work from the level of a mere shellcollector's catalogue to the rank of a work of reference of real scientific value.

Mr. Sowerby enumerates 740 species, and estimates that 323 of these are confined to South Africa, whilst 67 also occur in European seas, and 340 have been found on other coasts. Unfortunately, it is our disagreeable duty to point out that this record does not include "all the known species," and hence is not what the author fully intended it to be, viz., as complete as possible." An important paper by Von Martens1 appears to have been overlooked, for there are about thirty species named in it, including some which were then new, not mentioned by Mr. Sowerby. Still more remarkable is the omission of the new forms described by Mr. Watson in his report upon the Scaphopoda and Gastropoda, obtained during the voyage of the Challenger. Davidson's "Monograph of recent Brachiopoda," had it been more closely scanned, would have yielded not only two species reputed to have come from the Cape, but also Terebratulina Davidsoni, King, the type specimens of which, dredged on the Agulhas Bank, were passed on to their describer by Mr. G. B. Sowerby (the elder, we presume) in 1871.

A number of species have been recorded by Mr. E. A. Smith in an appendix to a "Report on the Marine Molluscan Fauna of the Island of St. Helena," as found there on what is locally known as "Sea-horn." This substance appears to consist of portions of a large species of Tangle, probably Echlonia buccinalis, which occurs at the Cape, whence it drifts to St. Helena. Some allusion should have been made to these forms. Hints might also have been gleaned from the same report, which deserves to be more widely known than seemingly it is, of undoubted South African species whose names do not appear in Mr. Sowerby's catalogue.

The presence of a good index, while it obviates the necessity, does not abolish the desirability of a good classification, and, in the present state of our knowledge in matters conchological, that of Woodward's Manual is hardly up to date; it is somewhat late in the day to find Dentalium still in its old place in the Gastropoda.

Some few changes in nomenclature are made in deference to the law of priority, and these are set forth at the end of the preface. Amongst them is Ovula, Bruguière, 1789=Ovulum, Sowerby, &c., though, according to some, Ovula is itself a synonym for Amphiperas, Gronovius, 1781; Calliostoma is erroneously attributed to Bruguière instead of Swainson.

There are also some oversights in the text, as, for instance, "Columbella cerealis, Menke (Buccinum), Krauss ...=C. Kraussii, Sowerby," where, since Menke's name was given merely in MS., Sowerby's name stands, having four years' priority over Krauss's; Triforis is treated as though of the masculine gender; whilst the references to 'figures in various works" require careful checking.

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"Ueber einige südafrikanische Mollusken nach der Sammlung von Dr. G. Fritsch." Jahrb. Deutsch. Malak. Gesell. 1874, pp. 119-146. - Proc. Zool. Soc. 1895, pp. 247-317.

As regards the figures that accompany the work itself, it is a matter for regret that they cannot be commended. Few objects are more difficult to draw or require more skill in their delineation than do the shells of mollusca, and the amateur is rarely able to do them justice. The want of finish in the present instance is all the more noticeable from the contrast they afford to the rest of the "get up" of the work, which is admirable.

These shortcomings are not thus dwelt on in any captious spirit, but are pointed out in the friendly hope that a future edition of the work may shortly be forthcoming, in which the defects of the present one, compiled under great difficulties and at much disadvantage, may be made good and a really complete catalogue result.

OUR BOOK SHELF.

(BV)2.

The Framework of Chemistry. Part I. By W. M. Williams, M.A. (London: George Bell and Sons, 1892.)

THIS is the first part of a book which has been specially written as a supplement to the oral lessons and experimental demonstrations given by a teacher. It is intended to contain nothing but what is absolutely necessary to give definite and precise impressions regarding the salient points of the lessons, all details relating to laboratory manipulation being omitted. The more important introductory facts, divested of theoretical considerations, are first discussed, then come "atoms and molecules," treated in an elementary fashion and leading the way to the explanation of the use of symbols and formulæ.

How the system adopted by the author will work out can only be ascertained when the other parts are to hand. | So far as the information in the present volume goes, it is to a great extent useful and clearly stated.

Objection may be taken to the classification of solutions as mechanical and chemical, for, were it for no other reason, it is still a disputed point whether any solution may be considered a mixture.

The concise style of the book lends itself to incomplete statements. For instance, to say that one of the oxides of carbon" contains exactly twice as much oxygen as the other," is hardly accurate; a constant quantity of carbon is essential to the accurate conception of the facts. The most serious blunder made by the author lies in the confusion of force and energy. This is manifest in statements involving the conversion of "chemical force " into an "equivalent amount of heat" or of "electrical force," and culminates in the assertion that "Force, like matter, cannot be destroyed.”

The Beauties of Nature, and the Wonders of the World we Live In. By the Right Hon. Sir John Lubbock, Bart. M.P., F.R.S. (London: Macmillan and Co., 1892.) So many writers of the present day adopt a pessimistic tone that a pleasant impression is always produced by Sir John Lubbock's genial and imperturbable optimism. In the present volume he undertakes to show how many sources of interest men might find in the world around them, if they would only take the trouble to train themselves to appreciate the scientific significance of ordinary facts. He begins with a study of animal life, and has much that is fresh and suggestive to say about various aspects of the subject. Then there are chapters on plant life, woods and fields, mountains, water, rivers and lakes, the sea, and the starry heavens. The volume is written in the clear, frank style with which all readers of Sir John Lubbock's books are familiar, and it ought

Algebra for Beginners. By H. S. Hall and S. R. Knight (London: Macmillan & Co. 1892.)

THIS work is intended as an "easy introduction" to the being treated on lines similar to those of the last-mentioned author's "Elementary Algebra for Schools," and, besides book, is published in a cheaper form. The idea throughout seems to have been to present the beginner with the practical side of the subject, and with this intention the examples are made as interesting as such examples cau be. The usual sequence has not here been strictly adhered to; but a beginner will find that he will still be able to reach the "as far as quadratic equations" limit. It is needless to say that the explanations are stated in clear and simple language, while the examples are all new. That this book will be widely used is undoubted, for it will form an excellent forerunner to the more advanced one referred to above.

Introduction to Physiological Psychology. By Dr. Theodor Ziehen. Translated by C. C. van Liew and Dr. Otto Beyer. (London: Swan Sonnenschein and Co. 1892.)

IN reviewing the book of which this is a translation (NATURE, vol. xliv. p. 145), we pointed out that such a book was badly wanted in English. We are glad, therefore, to welcome a translation of Dr. Ziehen's work, which will serve well as an introduction to the new science of physiological psychology.

LETTERS TO THE EDITOR.

[The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertakt 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 Volucella as Examples of Aggressive Mimicry. mimicry is the fact that they were first used to support the AN interesting point in the Volucella as examples of aggressive teleological theories of an earlier day, and were subsequently claimed by natural selection. Thus Messrs. Kirby and Spence speak of them (Second Edition, 1817, vol. ii., p. 223) as affording "a beautiful instance of the wisdom of Providence in adapting means to their end ;" and after describing the resem blance of the flies to the bees, they continue, “Thus has the Author of nature provided that they may enter these nests and deposit their eggs undiscovered. Did these intruders venture themselves amongst the humble bees in a less kindred form. their lives would probably pay the forfeit of their presumption." In this theory of Providence it is hard to see where the bees come in. In 1867, A. R. Wallace published an article on

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Mimicry and other Protective Resemblances among Animals,” which was in 1875 republished in his "Essays on Natural Selection." In this essay (p. 75 of the volume) he spoke of this interpretation as the only case in which an example of mimicry had been "thought to be useful, and to have been de signed as a means to a definite and intelligible purpose. accepts it as a product of natural selection, and since that time it has been constantly used as a well-known example of this principle, so well known, indeed, that the history of it became unnecessary in any publication where space was an object. I neither originated the principle of aggressive mimicry not the Volucella as examples of it, although I accepted, and stil accept, both. Under these circumstances I must, in justice to Kirby and Spence and A. R. Wallace, repudiate the discovery of a significance I should have been proud to have made, be which was made, as a matter of fact, about half a century before I was born. It is only fair to these writers to say this, for Mr Bateson, although mentioning Kirby and Spence, seems