COPYRIGHT, 1921, BY YALE UNIVERSITY PRESS
PRINTED IN THE UNITED STATES OF AMERICA
First Published, December, 1921.
Second Printing, June 1922.
Third Printing, October 1922.
Fourth Printing, January 1925.
Fifth Printing, October 1925.
Sixth Printing, March 1928.
Seventh Printing, March 1931.
Eighth Printing, October 1932.
Ninth Printing, September 1937.
Tenth Printing, July 1939.
Eleventh Printing, November 1941.
All rights reserved. This book may not be reproduced, in whole or in part, in any form (except by reviewers for the public press), without written permission from the publishers.
