Note. — The parts of this work appeared as follows : — 



Part I., 7th November, 1919 ; 

 Part II., 5th January, 1920 ; 

 Part III., 25th March, 1920 

 Part IV., 27th May, 1920 ; 

 Part v., ist July, 1920 ; and 

 Part VI., 1st September, 1920. 



