4 PREFACE TO FIRST EDITION. 



Flora of the United States" (Britton & Brown); the publica- 

 tions of the Division of Forestry of the Department of Agri- 

 culture; "Baume und Straucher des Waldes" (Hempel & Wil- 

 helm) ; and Flora von Dentschland, Oesterreich u. d. Schweiz 

 (Prof. Dr. Thome). 



S. B. G. 



University of Minnesota, 



St. Anthony- Park, 



July 29, 1898. 



