SCIE:NCE

LETTERS Use of Energy: R. W. Jacksvon:, P. K. Hanley; Ecology: P. B. .Scar:s Line;arAlgebral Problem: M. 7'laibcsonl 360

EDITORIAL M'ass Tran1stfer and Urbhan Problenms: L. IS. Savas 365

ARTICLES Liquid Hydrogen as a Fuel tfor the FuLture: L. W. Joncs 367

The Sun's Work in a Cornfield: E. Lemtlotn, D. W. Stewatrt, R. W. Shawcroft 371

EduLcation and Science in North Vietnanm: A. W. Galston and L. Signier 379

NEWS AND COMMENT

RESEARCH TOPICS

BOOK REVIEWS

MagrudLer in White House: SST Man Pl'ans News Technology Take-Off

Cancer Legislation: Pro-NIH Bill Advances in House

Human En\vironment C(oniterence: The Rush tor Influence

The 1971 Nobel Prize lor Medicine or Physiology: 1. H. Pastuta

Glohbl Meteorology (11): Numllerical Models of the Atmosphere

Science in Amnierican .Societv and Science in Aieri (ca, reviewdl by H. S. Miller;other reviews hy P. F. Brun.s.svar,( R. D. O'Bricn, B. M. Carlson, W. A. Reynolds:Books Receivecl

REPORTS A NIodel for PIlate Tectonic Evolution of Mantle Lavers: W. R. Dickinson an1dW. C. Llitli

Hyperfine Zeeman Effect Atomic Ahsorption Spectrometer for Mercury: E'. Haideishi,and R. D. McLaughlin

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BOARD OF DIRECTORS ATHELSTAN SPILHAUS MINA REES GLENN T. SEABORG DAVID BLACKWELL LEWIS M. BRANSCOMBRetiring President, Chairman President President-Elect RICHARD H. BOLT BARRY COMMONER

VICE PRESIDENTS AND MATHEMATICS (A) PHYSICS (B) CHEMISTRY (C) ASTRONOMY (D)SECTION SECRETARIES Henry 0. Pollak Gaylord P. Harnwell Charles C. Price Laurence W. FredrickF. A. Ficken Albert M. Stone Leo Schubert Arlo U. Landolt

PSYCHOLOGY (I) SOCIAL AND ECONOMIC SCIENCES (K) HISTORY AND PHILOSOPHY OF SCIENCE (L)James E. Deese Daniel P. Moynihan Cyril SmithWilliam D. Garvey Harvey Sapolsky Raymond J. Seeger

PHARMACEUTICAL SCIENCES (Npl AGRICULTURE (U) INDUSTRIAL SCIENCE (P) EDUCATION (Q)Wallace L. Guess Matthias Stelly Burton V. Dean J. David LockardJohn Autian Michael A. Farrell Jordan D. Lewis Phillip R. Fordyce

DIVISIONS ALASKA DIVISION PACIFIC DIVISION SOUTHWESTERN AND ROCKY MOUNTAIN DIVISIONLaurence Iving Irma Duncan George E. Lindsay Robert C. Miller John R. Lacher Marlowe G. AndersonPresident Executive Secretary President Secretary President Executive Secretary

SCIENCE is published weekly, except the last week in December, but with an extra issue on the third Tuesday in November, by the American Association for the Advancement ofScience, 1515 Massachusetts Ave., NW, Washington, D.C. 20005. Now combined with The Scientific MonthlIyR. Second-class postage paid at Washington, D.C. Copyright © 1971 bythe American Association for the Advancement of Science. Annual subscription $20; foreign postage: Americas $3; overseas $5; air freight to Europe, North America, Near East $16;single copies $1 (back issues, $2) except Guide to Scientific Instruments which is $4. School year subscription: 9 months, $15; 10 months, $16.75. Provide 4 weeks notice forchange of address, giving new and old address and zip codes. Send a recent address label. SCIENCE is indexed in the Reader's Guide to Periodical Literature.

AMERICN'ASSOCIATIoN Fo THE ADVANCEMENT oF SCIENCE

Riboflavin Ph-otosensitized Oxidation of 2,4-Dichlorophenol: Assessment ofPossible Chlorinated Dioxin Formation: J. R. Plimmer and U. 1. Klingebiel 407

Dopamine: Release from the Brain in vivo by Amantadine: P. F. Von Voigtlanlderand K. E. Moore 408

Differences in the Distribution of Catecholamine Varicosities in Cat and RatReticular Formation: J. R. Sladek, Jr. 410

Freezing and Melting of Lipid Bilayers and the Mode of Action of Nonactin,Valinomycin, and Gramicidin: S. Krasne, G. Eisenttlan, G. Szabo 412

Morphological Basis for a Mechanical Linkage in Otolithic Receptor Transductionin the Frog: D. E. Hillinan and E. R. Lewis 416

MolecLular Structure of Starch-Type Polysaccharides from Hericiiutm ramosulmt andHericiui,nl coralloides: D. A. McCracken and J. L. Dodd 419

Simian Tumor Virus Isolate: Demonstration of Cytopathic Effects in vitro:D. L. Fine, J. C. Lanidoni, M. T. Kubicek ........ 420

Disposition of Morphine in Man: S. Spector and E. S. Vesell 421

Intestinal Secretion: Stimulation by Peptides: G. 0. Barbezat and M. l. Grossmnanl 422

Inhibition of Normal Growth by Chronic Administration of A-9-Tetrahydrocannabinol:F. J. Manniinlg et al. 424

Growth Effects of Vanadium in the Rat: K. Schwarz and D. B. Milmle 426

Social Behavior of Monkeys Selectively Depleted of Monoamines:D .E.R edm iotnd, Jr., et al . ........................................ 428

Operant Conditioning of Specific Patterns of Neural and Muscular Activity:E. E. Fetz and D. V. Finocchio 1.

Technical Comments: Redwoods: A Population Model Debunked:P. F. Brussard et al.; K. Halbachl; J. E. Diemn and J. L. McGregor 435

ASSOCIATION AFFAIRS Application of Science in the Management of National Parks: T. Sudia;Indicators of Environmental Quality: W. A. Thotmias; Mineral Elementsin the Food Chain: M. A. Fatrrell 437

CARYL P. HASKINSPHYLLIS V. PARKINS

GEOLOGY AND GEOGRAPHY (E)Ellis 1. YochelsonWilliam E. BensonENGINEERING (M;Newman A. HallRaynor L. DuncombeINFORMATION ANDCOMMUNICATION (T)

Edward L. BradyScott Adams

LEONARD M. RIESER WILLIAM T. GOLDENKENNETH V. THIMANN Treasurer

BIOLOGICAL SCIENCES (FG)George Sprugel, Jr.Richard J. Goss

MEDICAL SCIENCES (N) DEfGeorge B. Koelle HLenF. Douglas Lawrason ShoSTATISTICS (U) ATMOSPHEIElizabeth Scott SCIENCEEzra Galser Thomas F.

Louis J. 8;

WILLIAM BEVANExecutive Officer

ANTHROPOLOGY (H)Ward GoodenoughAnthony Leeds

NTISTRY (Nd)nry W. ScherpIolm PearlmanRIC AND HYDROSPHERICES (W)Malone

Yattan

COVER

C'iliary tufts which protrude from thesensory surface of vestibular receptorcells are minute mechanical units. Theability of each tuft to deform the sur-face membrane of its receptor cellindicates a mechanism for transduc-tion (X 7000). See page 416. [D. E.Hillman, University of Iowa; E.R. Lewis, University of California,Berkeley.]

The American Association for the Advancement of Science was founded in 1848 and incorporated in1874. Its obiects are to further the work of scientists, to facilitate cooperation among them, toimprove the effectiveness of science in the promotion of human welfare, and to increase public under-standing and appreciation of the importance and promise of the methods of science in human progress.

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22 October 1971, Volume 174, Number 4007

AMERICAN ASSOCIATION FORTHE ADVANCEMENT OF SCIENCE

Science serves its readers as a forum for thepresentation and discussion of important issuesrelated to the advancement of science, includingthe presentation of minority or conflicting pointsof view, rather than by publishing only materialon which a consenstus has been reached. Accord-ingly, all articles published in Scienice-includingeditorials, news and comment, and book reviews-are signed and reflect the individual views of theauthors and not official points of view adopted bythe AAAS or the institutions with which the authorsare affiliated.

Editorial Board

1971

THOMAS EISNERAMITAI ETZIONIEMIL HAURYDANIEL KOSHLAND, JR.

ALFRED BROWNJAMES F. CROWTHOMSAS KUHNELLloT-r W. MONTROLL

NEAL MILLERBRUCE MURRAYJOHN R. PIERCENIAXINE SINGER

1972FRANK PRESSFRANK W. PUTNAMWALTER 0. ROBERTS

Editorial Staff

EditorPHILIP H. ABELSON

Piublisher Blsiness ManiagerWILLIAM BEVAN i-hANS NUSSBAUM

Mallagi,ig Editor: ROBERT V. ORMES

Assistallt Editors: ELLEN E. MURPHY, JOHN E.RINGLE

Assistailt to tlie Etlitor: NANCY TEIMOURIANNews a,i(I Comment: JOHN WALSHi, ROBERT J.

BAZELL*, DEBORAH SHAPLEY, ROBERT GILLETl-E, NICH-OLAS WADE, CONSTANCE HOLDEN, SCHERRAINE MACK

Researlch Topics: ALLEN L. HAMMONDBook Ret iews: SYLVIA EBERHART, KA1HERINE Liv-

INGSTON, KAThIIRYN MOU'I'ONCover Editor: GRAYLCE FINGER

Editoriol Assistants: MI ARGARET ALLEN, ISABELLABOULDIN, BLAIR BURNS, ELEANORE BUTZ, RONNACLINE. MARY DORFMAN, JUDITH GIVELBER, MARLENEGLESER, CORRINE HARRIS, OLIVER HEATWOLE, CHRIS-TINE KARLIK, MARSHALL KA'F5IAN, MARGARET LLOYD,JANE MIINOR, DANIEL RABOVSKY, PATRICIA ROWE,LEAH RYAN, LOiS SCHMIi"r, RICHARD SOMMER, YA LiSWIGARI, ALICE THEILE

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SCIENCE

Mass Transfer and Urban Problems

Geophysicists are understandably excited because they have clearlydetected continental drift. This finding comes as no surprise to the pub-lic official, who has already observed that the island of Jamaica, a hugeexporter of bauxite, is gradually drifting-in the form of a unicellularlayer of aluminum beer cans-onto the United States and covering us.

Indeed, one way of looking at the problem of the urban environmentis from this mass-transfer point of view. An urban society is character-ized by the continuing transfer of substantial amounts of matter fromremote, uninhabited sites to urban centers. Thus, fuel, ore, and timber,as well as food, are extracted or harvested in distant, rural locations andUltimately transported to urban areas. There, after physical and chemicaltransformation, they are deposited within the urban environment as solid,liquid, and gaseous wastes, and OLur cities stagger under the resultingburden of polluted air and water and mounting piles of solid refuse.

Yet, as a matter of public policy, our society perversely encouragesand subsidizes this process of mass transfer. We grant generous depletionallowances instead of levying prohibitive depletion penalties. A pound ofiron as ore is less costly to transport than a pound of iron as scrap, arate preference enshrined in federally prescribed interstate tariffs. Thus,althouLgh recycling presents itself as a way of reducing the overload onouLr environment, our system discourages recycling and rewards profligateconsumption. The requLired national changes are obvious, but the politicalwill is generally lacking. One hopeful sign is the recent legislation inNew York City which discriminates in favor of manufacturers who userecycled material in paper products purchased by the city government.

At the municipal level, a refuLse-collection service that is paid for ex-CluLsively by real estate taxes offers no incentive to reduce the amountof refuse that is generated; whether one produces a lot of refuse or alittle makes no difference, for it is removed "free of charge." The re-suLlt, again, is that we encouLrage indiscriminate production of waste inouLr "effluent society" at the same time that we are running out of landfor waste disposal. To repair this portion of our malfunctioning system,we ouLght to either impose a disposal tax-collected at the manufacturingsouLrce on all inedible products (with the tax proportional to the dif-fiCLulty of disposal), or else charge the consumer directly, by the pound,for the waste he nonchalantly bequeaths to his munitipality.The challenge before us is to design and implement the right kind of

regulatory feedback mechanisms, through enlightened tax and transportpolicies, so that we can reduce the rate of depletion of our resources,increase rccycling, reduce the amount of material that has to be handledin the cycle, and improve the qLlality of our urban environment.-E. S.SAVAS, First Depuity City Administrator, Office of the Mayor, 250 Broad-way, New York 10007