vi PREFACE 



available sources, much of it from personal correspondence. 

 The writer wishes to express his appreciation of the cordial and 

 ready response with which his numerous inquiries have been 

 met. He is under particular obligation to Director Charles H. 

 Judd, School of Education, the University of Chicago, for writ- 

 ing the introduction, and for his many helpful suggestions during 

 the progress of the work; to Mr. D. J. Crosby, United States 

 Department of Agriculture, for the critical reading of several 

 chapters, and for other assistance; to the United States Bureau 

 of Education, to the State Departments of Education, and to 

 many individuals who have furnished information not other- 

 wise accessible. 



BENJAMIN MARSHALL DAVIS 



MIAMI UNIVERSITY, OXFORD, OHIO 

 March, 1912 



