Copyright, 1905, by W. B. Saunders and Company. Reprinted February, 1906, September, 

 1906, and January, 1907. Revised, reprinted, and recopyrighted August, 1907. Re- 

 printed January, 1908, and October, 1908. Revised, reprinted, and recopyrighted 

 August, 1909. Reprinted January, 1910, and July, 1910. Revised, re 

 printed, and recopyrighted August, 1911. Reprinted January, 191 2 e 

 and October, 1912. Revised, reprinted, and recopyrighted 

 September, 1913. Reprinted August, 1914. Revised, 

 reprinted, and recopyrighted September, 1915. 

 Reprinted March, 1916, January, 1917, 

 May, 1917, and March, 1918. Re- 

 vised, reprinted, and recopy- 

 righted September, 1918 



Copyright, 1918, by W. B. Saunders Company 



Registered at Stationers' Hall, London, England 



Reprinted March, 1919 

 Reprinted September, 1919 



PRINTED IN AMERICA 



PRESS OF 



W. B. SAUNDERS COMPANY 

 PHILADELPHIA 



