iv 



SCIENCE.— ADVERTISEMENTS. 



JDLIEN'S IMPROVED LAPIDARY LATHES 



For SLICING and POLISHING rocks, minerals, fossils, 

 etc., and for GRINDING DOWN the same into micro- 

 scopical thin sections. Lathes, fitted to foot or power, con- 

 tain COMPLETE APPARATUS for the work. Send lor 

 illustrated catalogue. Rock sections for sale. 



GUSTAVUS D. JULIEN, 932 Bloomfield St., HOBOKEN, N. J. 



MARINE BIOLOGICAL LABORATORY 



Supply Department — 1. Zoolog^y— Preserved Material 



of all types of animals for class work or for the museum. 

 2. Botany — Preserved 3Iaterial of Algae, Fungi, Liver- 

 worts and Mosses. For price liets and all information ad- 

 dress GEO. M. GRAY, Curator Woods Holl, Mass. 



Ninth Revised Edition. Published Jan. 1901,. 



The Microscope and Microscopical Meifiods 



By SIMON HENRY QAQE, of Cornell University. 



Important changes have been made and the chapter on 

 Projection Microscope rewritten and more fully illustrated. 

 New figures of American microscopes and apparatus. 

 Postpaid 81.50 as for the 8th edition 



COMSTOCK PUBLISHING CO., Ithaca, N. Y. 



WANTED— Taxidermists, at the Field Co- 

 lumbian Museum, Chicago. Applicants 

 should give full particulars. Apply to the 

 Director. 



TypoWri'ter 



The Standard Visible Typewriter 



Its Record lias never been Equaled 



CATALOGUE FREE 



THE OLIVER TYPEWRITER COMPANY 

 310 Broadway, New York 



Leuckart=Chun Zoological Charts 



-Of- 



In vertebrates and Chun Charts of Vertebrates 



Price, mounted on linen, Duty Free, $1.75 each German Pamphlet on request 



ARTHUR H. THOMAS COMPANY, importers and Dealers 

 Microscopes and Laboratory Apparatus 12th and Walnut Sts., Ph ladelphia 



DUTY FREE 

 IMPORT A TION 



We import scientific instruments free of duty for col- 

 leges and ani'verstties from Societe Genevoise, Cam- 

 bridge Scientific Instrument Co., Max Kohl, Carl Zeiss 

 Optical Works, Dr. M. Th. Edelmann, Otto Wolff, 

 Hartmann & Braun, Siemens & Halske, and many other sources. 



We shall endea-vor to secure your business on the basis of moderate prices and to 

 keep it on the score of good service. An inquiry ivill receive a prompt reply. 



THE SCIENTIFIC SHOP albert b. porter 

 SCIENTIFIC INSTRUMENTS 322 Dearborn Street, CHICAGO 



