IV 



SCIENCE—ADVERTISEMENTS 



SCIENCE 



A Weekly Journal devoted to the Advemcement of 

 Science, publishing the official notices Eind pro- 

 ceedings of the American Association for 

 the Advancement of Science 



Published every Friday by 



THE SCIENCE PRESS 



LANCASTER, PA. GARRISON. N. Y. 



NEW YORK, N. Y. 



Entered in the post-office at I,ancaster, Pa as second-class 

 matter, under the act of March 3, 1879 



THE ELLEN RICHAKDS KESEARCH PRIZE of 



$1,000 is offered for award in the year 1922. Theses by 

 women based on independent laboratory research are 

 eligible for competition, and must reach the com- 

 mittee before February 25, 1922. 



For circulars of information and application 

 blank, apply to 



Dr. Lillian Welsli, 



Goucher College, Baltimore, Md. 



NOW READY 



The Physics of the Air 



By WILUAM J. HUMPHREYS, Ph.D. 



Professor of Meteorologioil Physics, United States 



Weather Bureau 



A rational and deductive treatise on the physics or 



the atmosphere. Of great value to meteorologists, 



physicists and the aviator. 



678 Pages, Illustrated, Index, 8vo. Price, ^5 

 Address orders and inquiries to 



THE FRANKLIN INSTITUTE 



PHILADELPHIA, U. S. A. 



THE COCCIDAE 



Tables for the Identification of the Subfamilies 



and Some of the More Important Genera 



and Species Together with Discussions 



of Their Anatomy and Life History 



By 

 ALEX. D. MncGILLlVRAY Ph.D. 



Pmf. of Systematic Entomology in the University of Illinois 

 Chapters devoted to near relatives of Coccids, Prep- 

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 of the Subfamilies and Tribes, Twenty-seven in all. 



8vo. Cloth. IX-)-502. $6.00 net 

 Sent prepaid upon receipt of price' Order direct from pnblishet 



SCARAB COMPANY 

 603 Michigan Ave. Urbana, Illinois 



CAYEUX'S PETROGRAPHY OF SEDIMENTARY ROCKS 



On account of exorbitant charges of the book im- 

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 of above work (reviewed Science, May 13, p. 459) for 

 anyone sending application accompanied by $7.00, be- 

 fore July 1. Any difference will be refunded or col- 

 lected. Have just imported direct for $5.75. An 

 American importer's price quoted was $10.00. 

 Marcus I. Goldman 

 tl. S. Geological Survey, Washington, D. C. 



FELLOWSHIP IN PHARMACOLOGY 

 The Department of Pharmacology of the Medical 

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 offers a fellowship, intended primarily for training 

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WANTED, in an Eastern college, a young man as 

 Assistant in Zoology (B.S. or M. S.). Must have 

 a fair knowledge of vertebrate morphology. State 

 qualifications. Salary $1500. 



Address U, Care of Science, Garrison, N.Y. 



PLANT BREEDER. (Ph.D., Asst. Professor) will 

 consider position here or abroad requiring teach- 

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 with part-time research 



Address X Y, care of Science. 



Large Induction Coil, 20 inch spark, 25 amperes, 

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Two 6-inch M. & W. X-Ray Tubes, |25. Adjust- 

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Tome School, Port Deposit, Md. 



WANTED : Assistant Professor of Zoology, a man 

 with Ph.D. degree and some experience, to teach Com- 

 parative Anatom5', Histology, Embryology, and re- 

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