SCIENCE—ADVERTISEMENTS 



THE 

 PRINCIPLES OF 



STRATIGRAPHY 



BY 

 AMADEUS W. GRABAU, S.M., S.D. 



PROFESSOR OF PALEONTOLOGY IN 

 COLUMBIA UNIVERSITY 



"Should be on the reference shelf of every col- 

 lege, normal •chool, and large high school in the 

 United States."— /ourna/ of Geography, Vol. XIII. 

 Jon. 1915. 



8v; IISO pagem, 264 iltattrationt. Prie; $7.S0 



DaaeriptiT* Circular Sent npan Reqnert 



K. G. SEILER & CO. 



NEW YORK CITY 



The Sarah Berliner 



Research Fellowship 



for Women 



A fellowship of the value of one thous- 

 and dollars is offered annually, available 

 for study and research in physics, chem- 

 istry or biology. Applicants must already 

 hold the degree of doctor of philosophy or 

 be similarly equipped for the work of fur- 

 ther research. Applications must be re- 

 ceived by the first of February of each 

 year. Further information may be ob- 

 tained from the chairman of the committee, 

 Mrs. Christine Ladd-Franklin, 527 

 Cathedral Parkway, New York. 



Teachers Wanted 



An Assistant Professor of Chemistrj', $1500; Instruc- 

 tor in Chemistry, $1300; Assistant Chemist, Labora- 

 tory Work, $1200. Instructor in Biology; Instructor 

 in Physios, $1200. Address 



The Interstate Teachers' Agency 



Macheca Bids:. New Orleans, La. 



The Microscope 



12th Edition, Published April 10, 1917 



Re-Written and largely Re-IIIuttrated 



Br SIMON HENRY GAGE of Cornell Unirardty 



Poitpald $3.00 



COMSTOCK PUBLISHING CO., Ithaca. N. Y. 



Memoirs af the Wistar Institute of Anatomy and 

 Biology. No. 6, 1915 



THE RAT 



Data and Reference Tables. 278 Pages. 89 Tables. 



Bibliography. 

 Compiled and Edited by HENRY H. DONALDSON. 



Postpaid $3.00. 



Philadelphia, Pa. 



The Wistar Institute 



The Ellen Richards Research Prize 



The Naples Table Association for Promoting 

 Laboratory Research by Women announces the offer 

 of a reseMch prize of $1000.00 for the best thesis 

 written by an American woman embodying new ob- 

 servations and new conclusions based on independent 

 laboratory research in Biology (including Psy- 

 chology), Chemistry or Physics. Papers published 

 before 1916 will not be considered and theses pre- 

 sented for a Ph.D. degree are not eligible. Theses 

 offered in competition must be in the hands of the 

 Chairman of the Committee on the Prize before 

 February 25, 1918. Application blanks may be ob- 

 tained from the secretary, Mrs. Ada Wing Mead, 

 823 Wayland Avenue, Providence, R. I. 



NATURAL HISTORY OF MAN 



18,000 Specimens illustrating the daily life of 

 Savage Races, many now extinct. Weapons, Orna- 

 ments, Deities, Currency, Carvings, Tools, etc. 

 Guaranteed localities and age. Type Collections 

 for Museums a Specialty. 



OLDMAN, 77 Brixton Hill, Londop, England 



MARINE BIOLOGICAL LABORATORY 



WOODS HOLE, MASS. 



Biological Material 



1. Zoology. Preserved material of all types of nnlniftlii 

 for class work and for the museum. 



2. Embryologry, Stages of some invertebrates, fishes (in- 

 eluding Acanthias, Ami a and Lepidosteus), Amphibia, and 

 Bome mammals. 



3. Botany. Preserved material of Algae, Fungi, Liver- 

 worts and Mosses. Price lists furnished on application to 



GEORGE M. GRAY, Curator, Woods Hole, Mass. 



JULIEN'S POWER LATHES 



COMPACT— ACCURATE— CURABLE 



TTm of Geologists, Mineralogists, eto., in SLICING 



and POIiISHINO all hard substanoas, rooks, eto., and 



ia preparation of MICEOSCOPIC THIN SECTIONS. 



GUSTAVUS D. JULIEN 



S Webster Terrace NEW ROCHELLE, N. Y. 



