Copyright, 1906, by W. B. Saunders Company. Revised, reprinted, and 



recopyrighted January, 1909. Reprinted September, 1910. 



Revised, reprinted, and recopyrighted' July, 1914. 



Reprinted September, 1915. Revised, 



reprinted, and recopyrighted 



September, 1917 



Copyright, 1917, by W. B. Saunders Company 



Reprinted May, 1920 



PRESS OF 



. B. SAUNDERS COMPANY 

 PHILADELPHIA , 



