Copyright, 1939, 1940, 1946, 1952, By The C. V. Mosby Company 



(All rights reserved) 



Third Edition Reprinted 



November, 1946 



June, 1947 



November, 1948 



February, 1951 



Printed in the 

 United States of America 



Press of 



The C. V. Mosby Company 



St. Louis 



