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SCIENCE.— ADVERTISEMENTS. 



JDLIEN'S IMPROVED LAPIDARY LATHES 



For SLICING and POLISHING rocks, minerals, fossils, 

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



MARINE BIOLOGICAL LABORATORY 



Sapply Department — I. Zoology — Preserved Material 



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



Ninth Revised Edition. Published Jan. 1901. 



The Microscope and Microscopical Methods 



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 S1.50 as for the 8th edition 



COMSTOCK PUBLISHINQ CO,, Ithaca, N. Y. 



NOW READV 



PHILOSOPHICAL TRANSACTIONS 



of the Royal Society of London. 



Series B, containing Papers of Biological Character. 



"Vol. 197, pp. 408, with 22 Plates. Price i 1 : 13 : 6d. 



London: HARRISON & SONS, 45 St. Martin's Lane, W. C. 



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