Can be seen by appointment at the following address :ADAM HILGER, Ltd., 75a Camden Road, London, N.W. AWARDED GOLD MEDAL ST. LOUIS EXHIBITION, 1904. Telegraphie Address :-“Sphericity, London." ILLUSTRATED LIST ("A") OF SPECTROSCOPES AND SPECTROSCOPIC ACCESSORIES GRATIS ON APPLICATION. 8, 9 & 10 HATTON GARDEN, LONDON, SCIENTIFIC INSTRUMENT MAKER WAR OFFICE, INDIA OFFICE, ADMIRALTY, &c. WHOLESALE MANUFACTURER { Meteorological and Scientific Instruments OF EVERY DESCRIPTION, INCLUDING STANDARD MERCURIAL BAROMETERS, STANDARD ANEROID BAROMETERS, STANDARD THERMOMETERS of every KIND, PUMPS BOTH FOR VACUUM & PRESSURE, Air Meters, Anemometers, Boiling Point Apparatus, Burettes, CATHETOMETERS, clinometers, Drawing Gauges, Hydrometers, MICROSCOPES, Plane FINDERS, SEXTANTS, Spectroscopes, Sphygmometers, Sunshine Recorders, THEODOLITES, Wind Vanes, &c., &c., &c. MADE TO ORDER. IS Exceptional Terms to Colleges, Institutions, &c. MACMILLAN & CO.'S BOOKS FOR STUDENTS OF ZOOLOGY. THE CAMBRIDGE NATURAL HISTORY. LEE COMPLETED IN TSK: D, F.R.S., INDU EDITED BY S. F. HARMER, Sc.D., F.R.S., AND A. E. SHIPLEY, M.A., F.R.S. TO BE COMPLETED IN TEN VOLUMES. Svo. PRICE 175. NET EACH. INSECTS. PART II. VOLUME VI. Hymenoptera continued (Tubulifera and Aculeata), ColeopFlatworms. By F. W. GAMBLE, M.Sc. Nemertines. By tera, Strepsiptera, Lepidoptera, Diptera, Aphanip Miss L. ShelDON. Threadworms, &c. By A. E. tera, Thysanoptera, Hemiptera, Anoplura. By David SHARP, M.A., F.R.S. FISHES, &e. VOLUME VII. Fishes (exclusive of the Systematic Account of Teleostei). By By A. E. T. W. BRIDGE, Sc.D., F.R.S. Fishes (Systematic Account of Teleostei). By G. A. Boulenger, FR.S. Sc.D., F.R.S. Hemichordata By S. F. HARMER, Sc.D., F.R.S. SHELLS. Ascidians and Amphioxus. By W. A. HERDMAN, 1 D.Sc., F.R.S. VOLUME III. AMPHIBIA & REPTILES. Molluscs and Brachiopods. By the Rev. A. H. COOKE, VOLUME VIII. By Hans Gadow, M.A., F.R.S. BIRDS. VOLUME IX. INSECTS & CENTIPEDES. By A. H. Evans, M.A. With numerous Illustrations by G. E. VOLUME V. LODGE. MAMMALIA. Peripatus. By Adam SEDGWICK, M.A. F.R.S. Myria. VOLUME X. pods. By F. G. SINCLAIR, M.A. Insects. Part 1. By Frank EVERS BEDDARD, M.A. Oxon., F.K.S., ViceBy DAVID SHARP, M.A., F.R.S. Secretary and Prosector of the Zoological Society of London. *. Volume I., dealing with PROTOZOA (including Sea Anemones, Jelly Fish, Star Fish, &c.), will be ready shortly, and Volume IV., dealing with SPIDERS, SCORPIONS, and CRUSTACEA, is in the Press. ELEMENTARY PRACTICAL' An INTRODUCTION to the OSTE ZOOLOGY. By Professor T. J. PARKER, D.Sc., OLOGY OF THE MAMMALIA. By Sir WILLIAM Edition. Revised with the assistance of Hans GADOW, Ph.D. Crown 8vo. 1os. 6d. TEXT-BOOK of COMPARATIVE Prof. ANATOMY, By Dr. ARNOLD LANG. With Preface by Dr. ERNST HAECKEL. Translated by H. M. and M. BER NARD. Vols. I. and II. (completing the Invertebrates). A TEXT-BOOK OF ZOOLOGY. By 8vo. 175. net. each. Professor T. J. PARKER, D.Sc., F.R.S., and Proses ELEMENTS of the COMPARATIVE sor W. A. HASWELL, M.A., D.Sc., F.R.S. In Two ANATOMY OF VERTEBRATES. Adapted from the Vols. With Illustrations. Medium 8vo, 36s. net. German of Professor WIEDERSHEIM." By Professor THE FOUNDATIONS OF ZOO W. NEWTON PARKER. With additions by the LOGY. By W. K. BROOKS, Ph.D., LL.D. 8vo. Author and Translator. 270 Woodcuts. Medium Sro. Second Edition. 125. 60. net. ros. 6d. net. INTRODUCTION TO ZOOLOGY. v | THE STRUCTURE of MAN: An IN DEX to his PAST HISTORY. By Professor WIEDBy C. B. and G. C. DAVENPORT. Crown 8vo. 6s. I ERSHEIM. Translated by H. M. BERNARD. The : LESSONS IN ELEMENTARY Translation, Edited and Annotated, and a Preface willen by Professor G. B. HOWES, F.R.S. With 105 Figures BIOLOGY. By Prof. T. J. PARKER, D.Sc., F.R.S. in the Text. Svo. 8s. net. Illustrated. Third Edition, revised. Crown 8vo. 1os. 6d. 1 A LA TREATISE ON COMPARATIVE A COURSE of INSTRUCTION in EMBRYOLOGY. By F. M. BALFOUR, F.R.S. 2 vols ZOOTOMY. Vertebrata. By Professor T. J. PARKER, 8vo. Vol. I. 18s. Vol. II. 215. D.Sc., F.R.S. With Illustrations. Crown 8vo. 8s. 6d. The ELEMENTS of EMBRYOLOGY. AN ATLAS OF PRACTICAL ELE By Sir MICHAEL FOSTER, K.C.B., M.D., F.R.S, MENTARY ZOOTOMY. By the late G. B. HOWES, ! and Professor F. M. BALFOUR, F.R.S. Second LL.D., Professor of Zoology, Royal College of Science, Edition, revised. Edited by A. SedgwICK, M.A., and London. With a Preface by Prof. HUXLEY. 4to. Ios, net. W. HEAPE, M.A. Illustrated. Crown 8vo. 1os. 6d. ELEMENTARY BIOLOGY. By T. H. The NATURAL HISTORY of the MARKETABLE MARINE FISHES of the BRITISH HUXLEY, F.R.S., and H. N. MARTIN, F.R.S. New ISLANDS. By J. T. CUNNINGHAM, M.A. With Edition. Revised and extended by the late G. B. Howes Preface by E. RAY LANKESTER, F.R.S. Illustrated.. and D. H. Scott. Crown 8vo. 10s. 6d. Medium 8vo. 75. 6d. net. PHOSES of INSECTS. By LORD AVEBURY, F.R.S. INSECTS. By Professor L. C. MIALL, F.RS Illustrated. Second Impression. Globe 8vo. 35. 62. WATKINS & DONCASTER, Naturalists and Manufacturers of CABINETS AND APPARATUS 19 LOMBARD ST., E.C., and 57 CHARING CROSS, S.W. ESTABLISHBD 1782. Prompt Payment of Olaims. BIR KBECK BANK FOR ENTOMOLOGY, BIRDS' EGGS AND SKINS, AND ALL BRANCHES OF NATURAL HISTORY Classes, &c. Workmen true to Nature. (Five Doors from Charing Cross.) IT New Catalogue (102 pp.) just iseien, post frre. TERN ESTABLISHED 1851. montbly balances when not drawn below £100. Southampton Buildings, High Holborn, W.C. British and Foreign In Polished Deal Boxes. Microscopic Objects. Specimens sent on approval. NEW CATALOGUES POST FREE. o of Scientific Subjects, LU from 6/- per dozen. PHOTOMICROGRAPHS. 600, 14/6 ; 1200, 25/6. See List. MICROSCOPICAL SLIDES, Botanical, Zoological, LO, &c., from 6s. per dozen. FLATTERS & GARNETT, Ltd., 48, DEANSGATE, And at CHURCH ROAD, LONGSIGHT, MANCHESTER. MICROSCOPICAL PETROGRAPHY. Gentlemen interested in the above study are invited to send to JAMES R. GREGORY & CO., 1 Kelso Place, Kensington Court, London, W., for a Prospectus of THE TWENTIETH CENTURY ATLAS OF MICROSCOPICAL PETROGRAPHY, now being issued in Twelve Monthly Parts, each Part containing Four Fine Hall Tone Plates, and also Four actual Rock Sections. Subscription in advance, elther Monthly, 71-; Quarterly, 211, or for the whole Series of 12 Monthly Parts & 48 Sections, 44 4s. MICROSCOPIC SLIDES. MARINE ORGANISMS, Hydroz a, Crustacea, Annelida, &c., polyps extended, without pressure, dark ground or opaque, very beautiful. List. Exhibition Groups of Diatomi, Petrological, & Disper al of Mr. HORNELL'S collection of Slides, Marine and MICROSCOPES, &c. Tel.:-1316 CENTRAL. LIVING SPECIMENS FOR THE MICROSCOPE. FREDK. JACKSON & Co. 14 CROSS STREET, MANCHESTER. Volvox, Spirogyra, Desmids, Diatoms, Amceba, Arcella, Actinosphærium, Vorticella, Stentor, Hydra, Floscularia, Stephanoceros, Melicerta, and many (Late MOTTERSHEAD & CO.), other specimens of Pond Life. Price is. per Tube, Post Free. Helix THOMAS BOLTON, 25 BALSALL HEATH ROAD, BIRMINGHAM. LABORATORY FURNISHERS, MARINE BIOLOGICAL ASSOCIATION Importers, Manufacturers, and Dealers in OF THE UNITED KINGDOM. CHEMICAL AND PHYSICAL APPARATUS THE LABORATORY, PLYMOUTH. of every Description. The following animals can always be supplied, either living FINE CHEMICALS, VOLUMETRIC SOLUTIONS or preserved by the best methods : Sycon ; Clava, Obelia, Sertularia ; Actinia, Tealia, Caryopbyllia, AlcyPLAIN AND STOPPERED BOTTLES. onium ; Hormiphora (preserved); Leptoplana; Lineus, "Ampbiporus, AND EVERY LABORATORY REQUIREMENT. Nereis, Aphrodite, Arenicola, Lanice, Terebella ; Lepas, ‘Balanus, Gammarus, Ligia Mysis, Nebalia, Carcinus ; Patella, Buccinum, Eledone, Illustrated Catalogue of Apparatus, with Price List of Pectens Bugula, Crisia, Pedicellina, Holothuria, Asterias, Echinus, Chemicals, free on application. Ascidia, Salpa (preserved), Scyllium, Raia, &c., &ć. For prices and more detailed lists apply to Biological Laboratory, Plymouth. THE DIRECTOR. NOTICE.-Advertisements and business letters for NATURE should be addressed to the Publishers; Editorial CHARGES FOR ADVERTISEMENTS. £ s. d. 65. d Yearly , , . 18 Yearly . . *Three Lines in Column . . 1 10 6 . 0 2 6 Quarter Page, or Hall Per Line after. o 091 a Column . Hall-yearly . 115 . . . 014 6 Half-yearly . . .0 15 6 One Sixteenth Page, or Eighth Col. 10 0 | Half a Page, or a Columa 3 5 o Quarterly . 7 61 Quarterly . . .o 8 o One Eighth Page, or Quarter Column .. 018 6 | Whcle Page . . . 66 • The first line being in heavy type is charged for as Two Lines. Cheques and Money Orders payable to MACMILLAN & CO., Limited. OFFICE: ST. MARTIN'S STREET, LONDON, W.C. GAIFFE IMPROVED WIMSHURST MACHINE. A Standard Instrument for Laboratory and Research Work. Gives absolutely uniform continuous current for X-Rays, High Frequency, Wave Current, &c. No enclosure (works in open air), no spindle, no sectors. Plates are readily detachable. Descriptive Pamphlet gratis on application from the Sole Agents for Great Britain and its ColoniesTHE MEDICAL SUPPLY ASSOCIATION, 228 GRAY'S INN ROAD, LONDON, W.c., where the apparatus may be seen working. CROSSLEY'S GAS ENGINES RECENTLY GREAT REDUCTION REMODELLED. Represents K and L CAS CONSUMED. types, giving 3.5 H.P. Up to the end of 1904. and 5 H.P over 51,000 gas and respectively. oil engines had been LIMITED ANCHESTER delivered, representImmediate Delivery ing about threefor Stock Sizes quarters of a million of Engines. actual horse-power, CROSSLEY BROS., LTD., OPENSHAW, MANCHESTER JUST PUBLISHED. Watson's New Price List of ElectroTherapeutical and Diagnostic Apparatus. The new edition is greatly enlarged, containing 10% pages fully describing and illustrating all standard and many new instruments at reduced prices, with notes to assist in the selection of apparatus. CORRESPONDENCE INVITED. W. WATSON & SONS, 313 High Holborn, London, W.C. Established 1837. Branches : 16 FORREST ROAD, EDINBURGH ; 2 EASY ROW, BIRMINGHAM. THE NEW NATURALISTS' CAMERA. Reflex Focussing for Ordinary or Telephoto. Lenses. ILLUSTRATED PROSPECTUS FREE J. H. DALLMEYER, Ltd., 25 Newman St., LONDON, W. MAKERS OF THE CELEBRATED DALLMEYER LENSES. Printed by Richard CLAY AND SONS, LIMITED, at 7 & 8 Bread Street Hill, Queen Victoria Street, in the City of London, and published by MACM1112) AND Co., LIMITED, at St. Martin's Street, London, W.C., and THE MACMILLAN COMPANY, 66 Fifth Avenue, New York.-THURSDAY, September 28 IUS orary A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE “ To the solid ground Of Nature trusts the mind which builds for aye." --WorIsWORTH. (All Rights are Reserved. VERLAG VON CUSTAV FISCHER IN JENA. NEW ILLUSTRATED CATALOGUE Soeben erschienen : (400 pages) of Von Dr. phil. et med. FRIEDRICH CZAPEK, 0. Ö. Prof. der Botanik in Zweiter Teil. 1905. Preis: 25 Mark, geb. 26 'Mark 50PF. Wissenschaftliche Ergebnisse der Deutschen Tiefsee- Expedition auf dem Dampfer “Valdivia” 1898-1899. Im Auftrage des Reichsamtes des Innern hrsg. von CARL CHUN, Prof. der Zoologie in Leipzig, Leiter der Expe. dirion B1, X., Liefg. I. u. II. " ung des vor Enderby-Land Also New Illustrated Catalogue of Sun-Dials, gedredschten Gesteinmateriales. Mit 1 Tafel und 6 Abbild. ungen im Text. Einzelpreis : 3 Mark, Vorzugspreis : 2.25 Mark. 32 pages, post free. Kapitän W. Sachse. Das Wiederauffinden der Bouvet e Insel durch die deutsche Tiefsee-Expe. dition. Mit 9 Tafeln und 1 Textabbildung. Einzelpreis: 18 Mark, Vorzugspreis: 16 Mark. Opticians to H.M. The King, H.R.H. The Prince of Wales, and Zur Erkenntnis der Kolloide. Ueber irreversible Hydrosole the Government, und Ultramikroskopie. Von RICHARD ZSIGMONDY. Mit 6 Textfiguren und 4 Tafeln. 3 FLEET STREET, LONDON, E.C. Preis: 4 Mark. LANTERNS & SLIDES, NEWTON & CO., LONG RANGE BAROMETERS Catalogue of Part II., free on application. THE DIAGONAL BAROMETER.-In this instrument the tube is much longer than usual, and at the point on the vertical column where in ordinary Mercurial Barometers the 28 inches would be marked, the tube is bent at an angle and the remaining 3 inches of the scale-viz. : 29, 30, and 31are extended over a tube 36 inches long. The mercury now moving diagonally instead of vertically, travels over 12 inches of the tube to every inch on the ver. tical scale. The slightest variation, even 'or" to which the scale is divided, is at once noticeable and can be easily read without the aid of a vernier or magnifier. Further Particulars and prices of this and other long NEGRETTI & ZAMBRA, 38 HOLBORN VIADUCT. JOHN J. GRIFFIN & SONS, Ltd., 20-26 SARDINIA ST., LINCOLN'S INN FIELDS, |