IX 



you yourself must do more by following up the hint, 

 enlarging your knowledge by wider studies of the 

 details of bud, flower, leaf, bark and general character- 

 istics of habits of growth. 



For this further study of details, the author strongly 

 recommends the use of such excellent text-books as 

 Gray's Field, Forest and Garden Botany, revised by 

 L. H. Bailey, Keeler's Our Native Trees (which is 

 equipped with excellent photographs), Apgar's Trees 

 of the Northern United States, Dame and Brooks's 

 Hand-book of the Trees of New England. Any of 

 these makes a good field book to take with you on 

 your rambles. If you wish to go further, the follow- 

 ing larger works will be found of great practical 

 value: London's Cyclopedia of Trees, Bailey's Cyclo- 

 pedia of Horticulture, Sargent's Silva of North Ameri- 

 ca, Britton and Brown's Flora of the Northeastern 

 United States, 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 the 

 author wishes to express his thanks for many cour- 

 tesies extended by Commissioner Richard Young of 

 the Park Department and for much practical aid 

 and valuable suggestions most cordially given by Mr. 

 John Whalley, Arboriculturist of Prospect Park and 

 Mr. Edward Kasold, Foreman Tree Planter of Pros- 

 pect Park. 



The author's acknowledgments for valuable inform- 

 ation regarding many of the rare varieties are also 

 hereby expressed to Dr. C. S. Sargent of the Arnold 



