IX 



these will make a good field book to take with you on 

 your rambles. Of the larger works, for reference, the 

 following are of great practical value: Bailey's "Cy- 

 clopedia of Horticulture"; Loudon's "Cyclopedia of 

 Trees"; Britton and Brown's "Flora of the North- 

 eastern United States"; and Emerson's "Report on 

 the Trees and Shrubs of Massachusetts." These can 

 be consulted in any good-sized library. 



In the preparation and completion of this book I 

 wish to express, with considerable emphasis, my 

 acknowledgment of the courtesy extended to me in 

 my field work by the Park Department ; especially by 

 Commissioner John J. Pallas, Secretary Willis Holly, 

 Assistant Secretary Col. Clinton H. Smith, Ex-Com- 

 missioner William R. Wilcox, and Ex-Secretary 

 George S. Terry. My thanks are also hereby tendered 

 to Mr. Robert Huhn, Foreman Gardener, of the Park 

 Department, for his very considerable aid, most 

 generously given. 



My acknowledgments for valuable information 

 regarding rare varieties are hereby tendered to Dr. 

 Charles H. Peck, State Botanist of New York; to 

 Messrs. Ellwanger and Barry of the Mount Hope Nur- 

 series, Rochester, N. Y. ; to the Shady Hill Nurseries, 

 Boston, Mass., and to Mr. Theodore Lawlor of 

 Flushing, N. Y. I wish also to express here my 

 appreciation of the very faithful and laborious work 

 of my wife, Nellie Marvin Peet, in the preparation and 

 completion of the index of this book. My thanks are 

 also acknowledged to Mr. Edward Yorke Farquhar, 



