VIII 
PREFACE. 
\ 
Campbell, of the University of Texas, has twice read the proofs, each time with 
the eye of a scholar and the heart of a friend. 
To the Carnegie Institution of Washington, I am no less grateful than I 
am indebted for the publication of this monograph. But for this kindness, 
the work could not have appeared in so full or in so handsome a form. 
To all these helpers and friends I tender my abiding gratitude. May they 
not have cause to regret their participation in the launching of this study! 
The University op Texas, 
Austin, Texas, February 15, 1913. 
Morgan Callaway, Jr. 
