Many of the designations used by manufacturers and sellers to distinguish
their products are claimed as trademarks. Where those designations appear
in this book and Perseus Publishing was aware of a trademark claim, the
designations have been printed in initial capital letters.

A CIP catalog record for this book is available from the Library of Congress.

ISBN: 0-7382-0276-2

Copyright © 2000 by Eric A. Davidson, Ph.D.

Foreword Copyright © 2000 by George M. Woodwell, Ph.D.

All rights reserved. No part of this publication may be reproduced, stored
in a retrieval system, or transmitted, in any form or by any means, elec-
tronic, mechanical, photocopying, recording, or otherwise, without the
prior written permission of the publisher. Printed in the United States of
America.

Perseus Publishing is a member of the Perseus Books Group

Text design by Heather Hutchison
Set in 11.5 -point New Caledonia by the Perseus Books Group

1 2 3 4 5 6 7 8 9 10--03 02 01 00 99

First printing, March 2000

Perseus Publishing books are available at special discounts for bulk pur-
chases in the U.S. by corporations, institutions, and other organizations.
For more information, please contact the Special Markets Department at
HarperCollins Publishers, 10 East 53rd Street, New York, NY 10022, or
call 1-212-207-7528.

Find Perseus Publishing on the World Wide Web at
http://www.perseuspublishing.com

-iv-