Purina
OAMMlL
FEEDING
Nutrition News
LABORATORY RATS
By H. C. Schaefer, Director Purina Laboratory Chow Research Rats have made a tremendous contribution to the science of nutrition. They are indispensable for the assay of certain vitamins and the biological assay of other nutrients. The nutrient requirements of laboratory rats are probably better known than those of any other animal used in research. Much of the fundamental information on amino acids, vitamins; and minerals was learned from investigations with rats. Purina Laboratory Chow was an outgrowth of this discovery. We recommend Purina Laboratory Chow as the sole ration for laboratory rats without any supplements. It is an excellent and economical diet for reproduction, lactation and growth. Since the use of diethylstilbestrol in cattle fattening rations, Purina Laboratory Chow is made at one of our mills where no estrogens are used. As an extra precaution, Laboratory Chow is being biologically assayed to make sure it contains no estrogenic activity. This is of special significance to investigators in the endocrine and cancer fields. Laboratory Chow can be obtained in several different forms for the convenience of the investigator. The Checker form makes for easy and economical feeding. The meal form is a convenience for drug assays or oral administration for toxicology studies. For further information about the nutrient content of Purina Laboratory Chow, please see your local Purina Dealer or write to Special In dustry Sales, Ralston Purina Company, St. Louis 2, Missouri.
WITH OVER 5,000 DEALERS COAST TO COAST TO SERVE YOU
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New (4th) Edition
Marshall-Lazier Human Anatomy beautifully illustrated text for an elementary course in human anatomy. Form and function of the human body and the relationship of one part to another are explained with unusual clarity. Here is
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For the New (4th) Edition special attention has been given to the treatment of the neurosensory system. The organs of common sensation have been combined with the chapter on the nervous system. The section on the Endocrine System has also been completely rewritten. 25 new illustrations have been added. More than usual emphasis is placed on the joints and segments. Muscles are described functional groups, simplifying the task of the student, and making it easier for him remember.
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to
By CLYDE MARSHALL, M.D., Formerly Assistant Professor of Anatomy, Yale University. Revised by EDGAR L. LAZIER, Ph.D., Professor of Zoology, University of California at Los Angeles. 420 pages, 5'/2" x 8'!1", with 329 illustrations. New (4th) Edition!
Frobisher -Microbiology This text furnishes a firm foundation in the fundamentals of microbiology for the beginning student. Part I introduces the student to the 8 groups of microorganisms, describing their size, structure and activities. Part II presents microscopic methods with full details on how one studies microorganisms in the laboratory, how they grow, their biochemical and physiologic aspects. Immunology is covered in Part III and antigen-antibody reactions discussed. With bacteria as the basis, Part IV discusses such biological phenomena as evolution, autotrophy, heterotrophy, photosynthesis, chemosynthesis, ecology of microorganisms, etc. The fifth and final part pictures the special environments in which microorganisms occur. By MARTIN FROBISHER, JR., Sc.D., Special Consultant, Bscteriology Branch, Communicable Disease Center, U.S. Public Health Service, Chamblee, Georgia; Associate Professor of Bacteriology, Emory University; Visiting Lecturer, Johns Hopkins School of Hygiene and Public Health. 633 pages, 6" x 9¼/4", with 253 illustrations. $6.00.
Fifth Edition!
W. B.
SAUNIDERS COMPANY
West Washington Square
Philadelphia 5
SCIENCE is published weekly by the AAAS, 1515 Massachusetts Ave., NW, Washington 5, D. C. Entered at the Lancaster, Pa., Post Office as second class matter under the act of 3 March 1879. Annual subscriptions: $7.50; foreign postage, $1; Canadian postage, 50g. 395 2 SEPT9EMBER 1955
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SCIENCE, VOL. 122
precision instruments for industrial and scientific laboratories STEREOSCOPIC
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microscopes remarkable clarity and depth Leitz STEREOSCOPIC Microscopes provide a truly threedimensional imdge of unsurpassed brilliance for examinations in the industrial and sciertific laborotory. They are engineered to give precision performance-assembly work on small parts, quality control, examinations in geology, mineralogy and in the biological field. * Wide field of view * Dual controls * Polarized, transmitted or incident light * Interpupillary adjustment - Inclined eyepieces for comfort Magnification ranges from 16 to 216X Superior L image quality through unique prism arrangement -
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HEATING microscopes
prec determination of melting behavior Simplified, accurate determination of the melting behavior of fuel ashes, slogs, glazes, enamels, glass and ceramics is assured with the Leitz HEATING Microscope, which permits visual observation and photographic recording of softening and melting phases. A series of photographs and temperature registra-tions provide laboratory evidence from which the viscosity of the specimen may be determined. Accessories avoiloble for incident light examination. Polarized light accessories availebb for strain ond stress analysis under high temperature used for control of bondage between glass (or ceramics) 1Ro
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E. LEITZ, INC., Dept. SC-9 468 Fourth Ave., New York 16, N. Y. Please send me additional information on the D HEATING Microscope D STEREOSCOPIC Microscope IN U F" t:
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E. LEITZ, INC. , 468 FOURTH AVENUE, NEW YORK 16, N. Y. Distributors of the world-famous products of Ernst Leitz, Wetzlar, Germany LENS ES * CAM ERAS * MICROSCOPES * BINOCULARS
2 SEI'TEMBER 1955
397
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Hypophosphite lodate Iodide Oleate Iron Salicylate Iron Selenide Iron Tetracarbonyl,
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The microprint idea can reduce the largest library to a small set of cards. Sixty conventional pages can go on a 3 x 5-inch card, with an abstract and filing data in ordinary-size type on the other side. The Kodagraph Microprint Reader lets you read in complete comfort. The screen is green and tilted 110 because that's the combination that seems to be easiest on the eyes. It's bright enough to use in ordinary room light. Several people can read at a time. You feed microprint cards into a Kodagraph Microprint Reader like paper into a typewriter -any size up to 812 x 14 inches. Many publishers offer microprint card editions. Many are also prepared to make microprint cards for you from your own literature and reports. To get started on a microprint system that can help solve the problems of debulking, speedy dissemination, and storage of literature and private internal data, mail the coupon below.
Isoarachidic Acid Isobehenic Acid Isocapric Acid Isocerotic Acid Isochrysene Isodurene Isolauric Acid Isolignoceric Acid
'Bh
NAME
ADDURtE
398
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Isoquercitrin
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Isoriboflavin Isostearic Acid Juglone Kaempferol Keratin Ketene Dimer x-Keto-b-aminovaleric acid
Ask for our new complete catalogue
FUNCTIONALLY DESIGNED WITH SAFETY IN MIND MIODEL GB2
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All metail construction A full fine adjustment with 12 revolutions Plano-concave mirror that can't fall out An elongated base to protect optics Achromatic objectives 16 mm (lOX) N.A. 0.27 4 mm (44X) N.A. 0.66 Huyghenian ocular (lOX) $1 18.00
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$106.20 each
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GENERAL BIOLOGY M ICROSCOPES
Business Photo Methods Division, Rochester 4, N. Y. Please send me the information checked: | Where I can see a Kodagraph Micropriti Re?ader. CD Folder on the Reader and sample micraprint card. List of publishers of microprint cards ar.J manufacturers of microprint cards
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Kodagraph Microprint Reader makes them a pleasure to read
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Isomyristic Acid Isonicotinic Acid Hydrazide Isopalmitic Acid Isoprene Sulfone Isopropylhydrazine Sulfate
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THE GRAF-APSCO CO. 5868 BROADWAY
CHICAGO 40, ILL. SCIEN'CE, VOL. 1"22
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Projects vivid true-color screen images for a solid hour without interruption! just flick the lever for instant choice of screen magnifications from 20 X to 3000 X (at 12 feet). You get the right light ... autonzatically ... because when you select an objective its matched condenser moves into perfect alignment. Screen images are bright and clear, critically detailed. Automatic electronic-feed arc lamp assures uniformly intense light for 60 minutes of uninterrupted viewing-you concentrate on the screen, not on the instrument. Efficient heat-control system eliminates need for colordistorting coolants . . . assures true-color images. Complete, SI 195.
Basic Illuminating Stand can be used, as shown here, with any microscope which has a substage condenser. Complete with built-in clamping device, built-in fixed mirror, Balcoted projection eyepiece, prism and light shield, $376.
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America's only complete optical source ... from glass to finished product.
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