found of service in identifying British wild flowers and discovering something about their affinities and the significance of their structure. These volumes have now been completely re-arranged, and the plates have all been newly drawn, so that the revised edition is substantially a new work. In the original books, plants were roughly arranged in the order of the seasons in which their flowers appear, but in the present volumes a more natural grouping is followed, series i. containing representatives of the plant families from the Buttercups to the Composites inclusive, and series ii. from the Composites to the Grasses and Ferns. This arrangement is much more instructive than the former one; and in connection with the descriptions of family characters given at the end of each volume it should facilitate the further study of plants in more elaborate works.

The coloured plates in the two volumes are, with few exceptions, very fine, and will enable the country rambler easily to identify the flowering plants he meets. In almost every case the pictures are truer to nature than those in the original volumes, though these left little cause for complaint. The picture, for instance, of Lady's Smock is much superior to that in the old edition; so is that of Germander Speedwell. The Chicory flower, however, is better represented in the old volume than in the new; and in neither is the illustration of Tamarisk satisfactory. The ideal way to depict flowers for purposes of identification would be to take tri-colour photographs of the flowers and reproduce them by the three-colour process of printing. This method, which has been successfully adopted in the illustration of a few natural history objects, might have been profitably used by Mr. Step instead of lithography. No doubt there are difficulties to be overcome, but they are not very great, and success should attend the work in which the advantages of colour photography are brought into requisition. But while we await these faithful photographic reproductions, it is good to possess Mr. Step's two pocket guides with their clear descriptions and plates, and we are glad that such attractive books exist to awaken interest in plant life.

Quiet Hours with Nature. By Mrs. Brightwen. Pp. xvi+271. (London: Fisher Unwin, 1904.) | Price 2s.

MRS. BRIGHTWEN'S books no longer need to be recommended to beginners in natural history. A fresh collection of her simple and sympathetic accounts of animal and vegetable life as studied and enjoyed in her own garden and park is sure to be welcome to all boys and girls who have once begun to take an intelligent interest in natural objects. All we need say about this volume is that, besides some pleasant papers about her tamed wild animals, including squirrels, field-voles, a rook, and even a stag-beetle, which followed his benefactor across the lawn, it contains others on the trees in her garden and some of the plants in her conservatory, all well calculated to arouse just such an interest in common things as may carry the young reader on to more exact and elaborate studies of nature. The book is charmingly illustrated by photographs and drawings.

One word of criticism may be allowed. It is surely as well, in introducing young folks to the study of nature, not to lead them to think that there is an essential difference between the "professional " entomologist or ornithologist and the ordinary observant field-naturalist; or if there be a real difference, it may be as well not to emphasise it. On p. 191 Mrs. Brightwen quotes a scientific description of the head of Eristalis tenax, with the comment :-" Now

this may be very interesting to a professional entomologist, but it does not convey much information to an ordinary reader, and yet this is the scientific description of my drone-flies, interesting creatures which I kept through a whole winter until they were coaxed into the circle of my winged friends." It is true that the description conveys but little to an " ' ordinary reader," but a very little trouble will make it convey a great deal, and this small amount of trouble, or of instruction if it can be had, is exactly what our young "nature-lovers" should be encouraged to face. As it happens, the example of Eristalis is a good one; for the history of its confusion with the bees is a most interesting one, showing how much delusion may arise, and not only delusion, but myth, merely from the want of a little knowledge of structure. Sammlung Schubert, XLII. Theorie der Electrizität und des Magnetismus. Vol. ii. By Prof. Dr. J. Classen. Pp. ix+251; with 53 figures. (Leipzig: G. J. Göschen 'sche Verlagshandlung, 1904.) Price 7 marks.

THIS forms the second part of an introductory textbook of electricity and magnetism in which chief stress is laid on the mathematical side. In this volume the Faraday-Maxwell conception of electrical phenomena still forms the central idea; but, since the representation of simple magnetic phenomena in terms of a distribution of energy in a medium presents considerable difficulty from the mathematical standpoint, the classical conception based on action at a distance is retained, but regarded merely as a mathematical device and not as a physical conception. In the section on electromagnetism the author adopts the special form of equations developed by Hertz in his paper on the fundamental equations of electromagnetism for bodies at rest, and expresses his strong opinion in favour of generally adopting these in all treatises of mathematical physics.

Only one part of Maxwell's characteristic treatment of the subject finds no place here, and that is his demonstration of the connection between the fundamental equations of electricity and the general Lagrangian equations of mechanics.

Vegetationsbilder. By Drs. G. Karsten and H. Schenck. Third series. Parts i.-iii., containing plates i.-xviii. (Jena: Gustav Fischer, 1905.) BOTANISTS who possess the first two series of the "Vegetationsbilder," or who have had the opportunity of admiring these magnificent series of photographic reproductions, will be glad to see that the third series is rapidly taking shape. The subject of epiphytic flower-gardens arising out of ants' nests, which formed part of a previous number, by Mr. E. Ule, is more fully treated in the first part of this series by the same authority. The ant-gardeners are species of Azteca, most often Azteca Traili and Camponotus femoratus. The plates represent different stages in the formation of the gardens; the plants which develop from seed brought in by the ants are chiefly aroids, bromeliads, and species of Gesneraceæ. In the second part Mr. E. A. Bessey presents a study of the sand-dunes, shifting and stationary, of Russian Turkestan with a vegetation of Calligonum, Salsola, Tamarix, and other xerophytes; the arboreous Salsola is particularly interesting. The photographs of Java, forming the third part, have been supplied by Prof. M. Büsgen, Mr. H. Jensen, and Dr. W. Busse. The subjects chosen include the teak forests, an expanse of the lotus, Nelumbium speciosum, a sand-dune bound by the creeping Spinifex squarrosus, and a bamboo forest.

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.] Remarkable Coelenterata from the West Coast of Ireland.

I HAVE been allowed to examine a small collection of Alcyonaria and Antipatharia that has been obtained by the fisheries branch of the Department of Agriculture for Ireland from deep water off the west coast of Ireland, and as this reveals some features of special interest I should be glad of an opportunity to write a short preliminary note upon it pending the examination of the species in detail.

The most interesting feature, perhaps, is the Coralliid, Pleurocorallium johnsoni, from 382 fathoms, about sixty miles off Achill Island. The family of precious corals to which this species belongs has hitherto only been obtained in the Mediterranean Sea, the Japanese seas, off Madeira and the Cape Verde islands, and in the Banda Sea. The specimens obtained by the Challenger in the Banda Sea were dead," but I have recently published a preliminary note on a new species of precious coral from deep water off the coast of Timor, which was captured alive" by the naturalists of the Siboga Expedition. The distinction between the genus Corallium, to which C. nobile, the precious coral of the Mediterranean, C. japonicum, and C. reginae, the new species from Timor, belong, and the genus Pleurocorallium is not a distinction of very great importance, and, as recently pointed out by Kishinouye, cannot, with convenience, be much longer maintained. If, however, for the present we retain the two generic names it must be noted that Corallium no longer maintains its monopoly of corals that are precious, as the species Pleurocorallium elatius yields some of the most valuable classes of coral obtained in the Japanese fishery. Both in Japanese waters and off the Cape Verde Islands the valuable and the commercially worthless Coralliidæ occur in the same fishing area, and consequently it would not be a matter for surprise if a renewed investigation of the locality from which the Irish Fishery Department obtained its specimen of Pleurocorallium johnsoni yielded some specimens of commercial value.

I should not like to suggest the prospect of a coral fishery off the coast of Ireland, as the sea is too stormy and the water too deep at the station from which the specimen came to render any such fishery commercially successful, but it would be a matter of considerable scientific interest to find that precious corals are growing within a few miles of our British coasts.

The second feature of interest is the occurrence in these waters of at least three species of Antipatharia. This group of Cœlenterata is one which I thought was entirely exotic. I can find no mention of any Antipatharians in any of the lists of the British marine fauna that I have examined, but perhaps some of your readers could inform me if I have overlooked any references to them. The species are, I believe, Cirrhipathes spiralis, Antipathella gracilis, and a species which I think must be new, but is allied to Stichopathes lütkeni in some respects.

new

Among the other interesting things in the collection are representatives of the alcyonarian genera Ceratoisis, Stachyodes, and Eunephthya, which I believe are to the British fauna. The two pennatulid genera Kophobelemnon and Umbellula were obtained in deep water off the west coast of Scotland by the Knight Errant (Kophobelemnon only) in 1880, and by the Triton in 1882. These also have now been found off the west coast of Ireland. Although these genera may now be included in the British fauna as being found within the British area as defined by the British Association committee of 1888, they really represent the fauna that is common to the "mud line of Murray of the eastern side of the North Atlantic Ocean.

Thus Pleurocorallium occurs off the Cape Verde Islands, Stachyodes off the Azores, Ceratoisis grayii off the coast

The smaller type cannot be said to be large in any sense of the word, and are like the minutest visible diplococci or biscuit-shaped cocci. They do not exceed this size to any great extent.

It is therefore desirable that the two types should not be identified, as their appearance, order of magnitude, structure and behaviour seem to be quite different."

M. Dubois has not noticed these, and therefore it seems to me that his claim to priority is quite irrelevant. Cambridge, October 21. JOHN BUTLER BURKE..

Border occasionally seen between Light and Dark Regions on Photographic Prints.

I HAVE once or twice been asked why photographs are apt to show a line or band or edging along the boundary of a bright and dark region. My assistant, Mr. E. E. Robinson, has thought of the reason, and it may be convenient to publish it. In a developed film the exposed portion perceptibly differs in thickness from the unacted-on portion, and accordingly the linear boundary of two contrasted regions may sometimes act as a cylindrical lens, and during printing either concentrate or disperse the light on the positive immediately beneath it. October 20.

OLIVER LOdge.

Terminology in Electro-physiology.

I WOULD deem it a favour to be assigned the space of a letter in order to make a suggestion in connection with the above still vexed subject.

It cannot be said that even now all is peace in the realm of electrical terminology as applied to physiological phenomena, in spite of Dr. Waller's helpful efforts in this direction. Dr. Waller's term "zincative" admirably expresses that a given region (A) of excited tissue is "electromotive like the zinc of a voltaic couple, 991 is, in fact, a source of current towards a region (B) of less excited or non-excited tissue (the current, of course, travelling in the tissue from the region A to the region B. and in the external circuit from the region B to the region A); but it leaves untouched the solution of the old muddle over the use of the signs + and

A+

-B

+

Confessedly, zincative" avoids any reference to + and, but every teacher of physiology knows that sconer or later the + and must appear, and with them all the ambiguities of negativity of action," &c., if the student is to make his notes agree " with his text-book. 1 "The Signs of Life from their Electrical Aspect," p. 17. (Murray, 1903

66

A large part of the difficulty arises from the different points of view taken by the electrician and the physiologist respectively, the electrician being concerned chiefly with the surfaces of conductors, the physiologist being

interested chiefly in the interiors of living tissues.

Thus the above expression, region A,' " is electrically ambiguous, for it may mean (1) either the surface of the region A, or (2) the interior of the same: certainly physiologically (and it may be also electrically) these are two very different things.

Are we speaking of surfaces or interiors when we talk of tissues and their electromotive states? This seems to me the gist of the initial obscurity.

In Dr. Waller's terminology A is "zincative" to B; but the electrically-minded student wishes to distribute his + and somehow. The electrician says A is negative

to B, because he is thinking of the surface at A to which current has been coming from B, as he finds by the galvanometer; but the physiologist, conceiving of what is going on inside the excited portion of tissue A, says, or should say, "A is electropositive to B," because he finds that current in the tissue must have come from A to B. The ambiguity is bound up with not distinguishing the surface from the interior.

Negativity of action" is then intelligible when it is distinctly laid down that it is only the surface of the active region that is being considered, for if the interior of the active tissue is thought of, then positivity of action must be the term descriptive of the electrical state.

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or

H

PROF. LANKESTER'S "EXTINCT ANIMALS.” 1 HOSE who, like the writer, had the good fortune to be present at the Royal Institution last Christmas and listened to Prof. Lankester's course of holiday lectures to young people will recall the fact that, although a goodly space was occupied by boys and girls from school, the theatre was elsewhere crammed with grown-ups," who were quite as much interested and amused as the juvenile audience for whom these discourses were really designed.

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It is, in fact, an open secret that quite elderly young people, as much as schoolboys and girls, enjoy their " "when given to them in a form easy ologies of digestion and with as few hard words as possible. Before the memory of those pleasant afternoon discourses has faded from our minds comes a reprint of them in book form, with reproductions of more than 200 of the illustrations given in the text as we saw them on the screen.

Every boy and girl who heard those lectures will wish for a copy of this charming book, and those who did not will now read with delight the pictured story of extinct animals for themselves; nor will the old boys "fail to take it up also.

Prof. Lankester explains that extinct animals are those which no longer exist in a living state. Animals, of course, die daily, and men too, but the lecturer tells us of extinct kinds of animals which no longer exist on the surface of the globe in a living state, although once they flourished and held their

own.

99 66

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for confusion is left; thus, A is internally electropositive to B, externally electronegative to B; B is internally electronegative to A, externally electropositive to A; for "externally,' galvanometrically may be used. Personally I think the use of the term negativity of action" is, especially if used in teaching, objectionable, because misleading and mysterious; "internal positivity of action " certainly seems to describe a real state; as terms, the one is but the converse of the other. I have, however, no more sympathy with those people who persist in finding "negativity of action " entirely meaningless than I have with those who will not understand negative pressure or negative quantities of any kind. DAVID FRASER HARRIS. Physiological Department, University, St. Andrews,

THE engineer's unit of force is equal to the earth's present attraction on the standard pound mass at a specified place, viz., for this country, London. Its magnitude is such that it produces unit acceleration when acting on a mass of 32.182.. lb., the engineer's unit of mass, sometimes called a slugg (sluggish). The formula MW/g, where M is the mass in sluggs, is true for any latitude, g being the acceleration of gravity there, and W the weight of the mass in pounds force, as would, for instance, be registered at the place by a massless spring balance which had been graduated in London. If the pound-poundal system of units is an absolute dynamical one, so also is the pound-slugg or engineer's system. THE REVIEWER.

He then informs his young friends of his own Museum and being fascinated by the huge head of an Ichthyosaurus from Lyme Regis with its large and bony-plated eyes, and its jaws, more than 3 feet in length, armed with powerful teeth.

Then the huge ground-sloth from South America attracted his wonder and admiration by its vast bulk, and he learnt that living upon the leaves of trees, but being too heavy to climb, it stood on the ground and pulled the trees down to it in order to feed on the young branches.

occur

Their remains, often with the bones of the same individual lying in one spot, in the vast "pampas formation" and in the alluvial mud of the great rivers such as the La Plata. Here, too, one meets with the giant armadillo, and another strange creature, called the Toxodon, like a huge guinea-pig, nearly as big as a rhinoceros, with tremendous chisellike teeth in front.

Prof. Lankester shows the thigh-bone of a giant reptile from North America more than 6 feet long (known as Atlantosaurus). What the size of the entire animal must have been we can best judge by paying a visit to the Cromwell Road Museum to see the skeleton of the Diplodocus lately set up there, which is So feet long and fully 14 feet high!

Passing rapidly over such forms as the ancient rhinoceros, the northern hippopotamus, the beaver, and great auk-once common in Britain, but now extinct--the author tells how zebras, quaggas, antelopes, and giraffes are being fast killed off in Africa by our sportsmen, whilst the dodo and

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Steller's sea-cow were eaten up long ago, like the giant tortoises, by our early voyagers, who victualled their ships with these rare animals.

The author next explains the causes which have brought about the migration of some animals and the extinction of others, and how changes of climate and

1 "Extinct Animals." By E Ray Lankester, M.A., LI.D., F.R.S. Pp. xxiv +332; with 218 illustrations. (London: Archibald Constable and Co., Ltd., 1905) Price 7s. 6d. ne'.

alterations of coast-lines have modified the existing lands so much that, as in our own islands, Great Britain and Ireland were, at no remote geological time, joined to France, and a continental, instead of an insular, climate prevailed here, with hotter summers and colder winters, suited to the mammoth

times than the more highly organised creatures now living on our earth.

י

More surprising still is it to find that the marine king-crabs (Limulus) and the scorpions (the latter at first aquatic, and afterwards terrestrial air-breathers) which are met with in the Upper Silurian rocks in America, Scotland, and Sweden have survived all the Old World changes of land and sea, the kingcrabs being still found living in the China and Indian seas and on the east coast of North America, and the scorpions have spread over the dry lands of North and South America, Africa, and other countries, and are so little changed in appearancewhole generations of other animals having appeared and disappeared entirelythat we might almost imagine they would go on for ever!

and reindeer which roved quite freely from land to land.

He explains what "fossils " are, and how the sedimentary deposits, in which extinct organisms occur, have been gradually laid down on the seafloor or along coast-lines. From minor changes he illustrates those greater ones which took place long since involving whole continents, so that where London now is was formerly the sea with marine shells and fishes, aptly reminding one of Lord Tennyson's lines:"Oh Earth! what changes hast thou seenThere where the great street roars

Was once the stillness of the central sea."

The story of the living and extinct elephants is well told, and we get the latest evidence of the progenitors of these very ancient prehistoric beasts, the result of Dr. Andrews's explorations and discoveries in the Fayûm, Egypt, which has carried their ancestry back to the Eocene Palæomastodon and Meritherium. Near to the elephants comes the wonderful Arsinöitherium, also from the Fayûm, with a pair of prodigious horns on the front of its skull, a form of animal which may possibly have had a short proboscis like the tapir (Fig. 1).

The birds and reptiles come in for due share of attention, and from their striking forms they add largely to the attractiveness of the illustrations. The comparison of the wings of Pterodactyle, bird and bat is most instructive, showing that reptiles, as well as mammals and birds, enjoyed the power of flight, as some also equally possess the power of swimming. Dimetrodon was undoubtedly swimming reptile (see Fig. 2).

Although it would be quite impossible for the author or anyone else to describe so vast a number of groups of living and extinct organisms in one series of lectures and afterwards to present them in book form with more than 200 illustrations in a single volume of 350 pages, at least Prof. Lankester knows how to give, in an attractive form, a vast amount of information agreeably, and to excite the interest of the merest tyro (whether young or old) and awaken a desire in him or her to learn more. Fortunately the author is also

a

Fishes, Mollusca, scorpions and Crustacea, also "sea-lilies," are dealt with in these lectures, and, as might naturally be expected, these simpler forms of life made their appearance far earlier in geological

director of the Natural History Museum, where he has abundant opportunities to add still more to our personal knowledge of extinct animals.

We give the book a hearty welcome, feeling sure that its perusal will draw many young recruits to the army of naturalists and many readers to its pages.

A

ASTRONOMY AND METEOROLOGY IN AUSTRALIA.

1

its share in tracing out the mysteries of the meteorology of the Indian Ocean. When we remember the powerful appeal of Sir J. Eliot at Cambridge for the cooperation of the British dominions in working out meteorological problems of the widest application the solution of which is foreshadowed by the suggestions of relationship between meteorological phenomena in different parts of the world and of their connection with solar changes, we can only hope that this pro

ments of the several States were invited, and there were present Sir Charles Todd, K.C.M.G., F.R.S. (Government astronomer for South Australia), who was called to the chair, Mr. H. A. Lenehan (acting Government astronomer for New South Wales), Mr. W. E. Cooke (Government astronomer for Western Australia), Mr. P. Baracchi (Government astronomer for Victoria), Mr. A. A. Spowers (chief surveyor for Queensland), and Mr. H. C. Kingsmill (Government meteorologist for Tasmania).

The report represents briefly, in the first place, the present arrangements for public astronomical and meteorological work in the several colonies and the provision for weather telegrams. It then proceeds to give its proposals for the future in twenty-two resolutions. Six of them refer to work in astronomy, magnetism, or seismology; the remaining sixteen indicate a scheme of organisation of the meteorological service of the Commonwealth. The scheme is framed on the idea of the establishment of a central federal institution for theoretical and scientific meteorology, "where the observations for the whole of Australia should be collected, discussed and published, and where all the higher problems of meteorological science may be investigated; but such institution should have nothing to do with the daily weather service and issue of forecasts." Duties connected with the latter services, according to the scheme, are to be entrusted to an official in each State; and to the regulation of those services and their relation to the telegraph service the greater number of the twenty-two recommendations are devoted.

Appendices give the separate views of Mr. Baracchi, Mr. Cooke, and Mr. Kingsmill upon some of the recommendations.

The really important matter is the proposal for a separate establishment for the discussion of meteorological observations for the whole Commonwealth. The idea will be warmly welcomed by all those who desire to see the multitudes of meteorological observations brought into the most effective relation with practical life. That such an institution should have nothing to do with the daily weather service and issue of forecasts" should probably be understood in an administrative sense. The ultimate effect of a scientific establishment upon forecasting would be a good deal more than nothing.

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The calling together of the Inter-State Conference for the business-like discussion of the organisation of astronomical and meteorological work will also be warmly applauded in this country. It is one more expression of the fact that work in astronomy and meteorology is of more than local interest and importance. While doubtless real progress in either must still depend upon individual energy and individual genius, exchange of material has become a recognised necessity, and exchange of ideas an indispensable assistance.

It is therefore a pleasant duty to chronicle the appearance of this most promising scheme, which will put the Australian Commonwealth in a position to continue the excellent work of Russell and take 1 Report of Inter-State Astronomical and Meteorological Conference, Adelaide, May, 1905 (By Authority, C. E. Bristow, Government Printer.)

prosecution of meteorological work is a step in the direction of a wider federation for a similar purpose.

On this planet, north and south and east and west are not so far apart that we in this country or our comrades in America or Africa can affect to regard the meteorological organisation of Australia as a question which does not concern us, and we shall watch the development of the scheme which is put forward, confident in its power of contributing in large measure to the pursuit of a common purpose in an organised W. N. S.

manner.

FERDINAND BARON VON RICHTHOFEN. THE unlooked-for death of this distinguished man of science has sent a thrill of deep regret all over the world among those who take interest in the progress of geology and geography. Though he had passed the limit of three-score years and ten, he remained up to the last so active in mind and body, so full of an almost youthful interest in the advances of science, so keenly solicitous and enthusiastic over the welfare of the institutions with which he was connected, that all who knew him looked forward to still many years during which his inspiration and guidance would continue to be at the service of those departments of investigation which have long been so deeply indebted to him; but this augury proved vain. While sitting at his writing table, apparently in his ordinary health, a sudden seizure deprived him of speech. Yet, as he remained otherwise fully conscious, it was hoped that the symptoms might soon pass away. A little later, however, another seizure attacked him during a deep sleep, and after two days and a half he passed peacefully away on October 6, without illness or suffering of any kind.

Belonging to a noble family that possesses large estates in Silesia, Richthofen was born there on May 5, 1833. His early education was received at a seminary under the management of Roman Catholic ecclesiastics, from which he passed to the University of Breslau and then to that of Berlin, where he took his degree of Doctor in Philosophy in 1856. By this time a study of the writings of Leopold von Buch and Alexander von Humboldt had kindled in him a vivid appreciation of the attractions of geological and geographical research. Like the two great masters from whom he drew his inspiration, he appears to have begun his career as an author by publishing some of the results of his investigation of eruptive rocks. His earliest papers, which began in 1856, dealt with the intrusive melaphyres of Moravia and the trachytes of Hungary.

Repairing to Vienna, he made the acquaintance of the geologists of that capital, and notably of the eminent director of the Austrian Geological Survey, Ritter von Hauer, with whom he formed a lasting friendship. He was induced to become a volunteer in this survey and to assist in working out the complicated structure of parts of the eastern Alps. He spent two busy seasons among the Dolomite Mountains, which in after years he looked back upon as one of the happiest periods of his life. The results of these field-surveys were embodied by him in his