Copyright, 1910, by W. B. Saunders Company. Reprinted July, 1911. 



Revised, reprinted, and recopyrighted November, 1913. Revised, 



reprinted, and recopyrighted November, 1916. Reprinted 



January, 1918, and October, 1919. Revised, reprinted, 



and recopyrighted March, 1920. 



Copyright, 1920, by W. B. Saunders Company 



PRESS OF 



V. B. SAUNDERS COMPANY 

 PHILADELPHIA 



