Copyright, 1955, by W. B. Saunders Company 



Copyright under the International Copyright Union 



All Rights Reserved. This book is protected 



by copyright. No part of it may be 



duplicated or reproduced in any manner 



without written permission from the publisher. 



Made in United States of America 

 Press of W. B. Saunders Company, Philadelphia 



Library of Congress Catalog Card Number: 55-5565 



