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ROCKS AND ROCK MINERALSBy the late Louis V. PIRssoN and ADOLPH KNOPF, Sterling Professor of Geology, YaleUniversity.

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TEXTBOOK OF GENERAL ZOOLOGYBy WINTERTON C. CuRTIs, Professor Emeritus of Zoology, and MARY J. GuTERIE, Professorof Zoology; both at the University of Missouri.

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ELEMENTARY NUCLEAR THEORYBy H. A. BuTIr, Professor of Physics, Cornell University.

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VOLUME I

ANNUAL REVIEWof MICROBIOLOGY

Available-November 1, 1947Published by

ANNUAL REVIEWS, INC.

C. E. CLITON, EditorS. RAPPEL, Associate Editor

H. A. BARKER, Associate Editor

EDITORIAL COMITTM. D. EATON E. C. STAKMANW. E. HERiELL W. H. TALAPERRoJ. M. SHERMAN C. B. vAN NIEL

CONTENTS:Morphology and Cytology of Protozoa, D. H. WenrichAntigenic Variation in the Protozoa and Bacteria, J. A.

1HarisonLife Cycle of Malarial Parasites, C. G. HuffVariation in Phytopathogenic Fungi, C. M. Christensen, E'

C. Stakmand J. J. ChristensenVariation in Phytopathogenic Viruses, L. 0. KunkelSome Aspects of the Problem of Growth Factors for Pro-

tozoa, A. LwoffBacterial Metabolism, D. D. WoodsNitrogen Metabolism, E. F. GaleIndustrial Fermentations, M. J. JohnsonQuaternary Ammonium Compounds, 0. Rahn and W. P.Van Eseltine

Antibiotics, R. G. Benedict and A. F. LanglykkeChemotherapeutic Agents, E. M. LourieImmunochemistry, H. P. TreffersSome Aspects of Active Immunization, J. FreundMedical and Epidemiological Aspects of Enteric Infection,

A. J. WeilThe Rickettsiae, N. H. Topping and C. C. ShepardRespiratory Viruses, T. Francis, Jr.

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Personnel Placementl .3

CHARGES FOR CLASSIFIED ADVERTISINGRegular setting 10 a word. Minimum charge $2.50 for each inser-tion. A box number counts asS words of the advertisement (e.g. 25words plus box number equals 33 words). Make checks payableto the A.A.A.S. All insertions must be accompanied by correctremittance and sent to the Adv. Dept. A.A.A.S. Please addressreplies as follows: Box number, SCIENCE, 1515 Mass. Ave., N.W.,Washington 5, D. C.

POSITIONS WANTED

The CaUforia Medical Bureau, Agency for scientific and lay personnel inmedicine, biology, chemistry, physics and allied sciences, supplies teachers,research workers, laboratory dieners, skilled office help. Prompt service.Registration free. Your patronage respectfully solicited. Tax CALbIox-NU MEDICAL BUREAU Agency, Arcade Medical Center, 696 ColoradoStreet, Pasadena 1, California.

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Geologist: PhD, well-known eastern women's college. Instructor, salary$2800. September 1948. Box 111 A, SCIENCE.

Editorial Asst: Requirements: Background in biology, biochemistryor medicine. editorial, writing and research experience; typing ability.Please send details, with photo, to Medical Editor, M. D. Anderson Hospitalfor Cancer Research, Houston, Texas.

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IPositions Open: (a) Medical mycologist; qualified to diagnose pathogenicfungi causing diseases; duties -include teaching; PhD or DSc degree; uni-versity medical school. (b) Bacteriologist; hospital and clinic havingimportant expansion program; outstanding research department; will con-sider candidate with Masters' degree. (c) Physicist; PhD trained andexperienced in electrical discharge in gases; advantageous if experienced inhigh frequency excitation of gaseous tubes, determination of Townsendcoefficients; university research appointment; 8400-500. (d) Medical copy-writer to take charge of newly-created department, advertising agency;East. (e) Statistician; PhD or MD; experienced preferably in cancerstatistics or biological research; cancer research department of graduateschool of medicine; $6000. (f) Immunologist with special training inbacteriology or immunology; research appointment, pharmaceutical com-pany; Middle West; PhD or MD required; $5200-7800. (g) Assistant pro-tessor of sanitary engineering; nine-month year; $4000; opportunity forteaching two months during summer would increase income $1000. S10-3,Medical Bureau (Burneice Larson, Director) Palmolive Building, Chicago11.

Personnel PlacementPOSITIONS OPEN

Good ossd open for clectronmicroscopists; spectrochemical analysts;process desin engineers; chemical process draftsmen; physical chemists:radioactivity, coiloid; physicists: gas kinetics, molecular spectroscopydegaeing, general classical, cathode ray tube, and recent grads BS M9and PhD.s Position Securing Bureau, Inc., 45 John Street, New Worikcity.

The Market PlaceBOOKS

SCIENTIF~-O'CT~ECHNICAL ' BOOKS-PERIOUdIC;ALSWanted to purchase, sets and runs. Foreign and Domestic.

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Baley's MAMMALS OF VIRGINIA, 432 pages 99 illustrations, 1946. 130kinds recent mammals-man, domestic and wild mammals. List of fossl.Bibliography 758 titles. Only publication devoted to Virginia zoology.85.00. John Wendell Bailey, 27 Willway Road, Richmond 21, Virginia.For Sale: Institut Pasteur. Annales. vols. 1-70 and index vols. 1-40 to-gether with Bulletin vols. 1-42. Mostly bound. Price on request. Zeitlinand Ver Brugge, 624 South Carondelet, Los Angeles 5, Calif.

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These advertisements will be read by more than25,000 scientists

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Growth RegulatorsFOR GARDEN, FIELD, AND ORCHARDBy JOHN W. MITCHELL & PAUL C. MARTH.Summarizes the progress in the field of syntheticplant hormones: their use in killing weeds, makingcuttings root readily, increasing fruit set, improvingstorage qualities. Illustrated, $2.50

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