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INTRODUCTION 8 
shall have been made the subject of more detailed investigations. 
Meanwhile, I present the results so far reached, utilizing the evi- 
dence derived from thousands of specimens of my own collecting 
and from field studies ranging from Canada to Virginia, with par- 
ticular concentration upon regions about the Potomac, about Lake 
Erie, the Massachusetts coast and New York City. 
Many asters in the herbarium give but little hint of their orig- 
inal texture, or develop a new color in the pappus, or change in 
many other ways. My method has been, therefore, to make de- 
tailed field notes of characters as well as of conditions of growth. 
Many characters presented by early stages or by radical and lower 
-cauline leaves, are lost at flowering time. I have therefore made 
it an especial object to secure the earliest spring growths and the 
intermediate stages. , 
Many asters have also seemed so variable that it has been 
questioned if the same rootstock would repeat the same characters 
at all in the growth of a second year. I have, therefore, kept the 
same plants under scrutiny for three successive seasons, sometimes 
for four years or more in succession, keeping certain sections under 
such repeated observation, including numerous localities near New 
York City; on Martha’s Vineyard; near Newton, Mass., on the 
Charles River ; in the White Mountains ; in the Lake Erie region 
(at Niagara gorge; in the Cattaraugus Indian reservation; near 
Silver Creek, and near Dunkirk, N. Y.); also about the Potomac 
River. 
Many courtesies have been received from the owners or cura- 
tors of various herbaria examined. I desire hereby to make special 
acknowledgments also to those who have kindly made collections 
for me, particularly to Mr, E. P. Bicknell, who has generously 
placed at my service his extensive field collections made about 
New York City. Mr. M. L. Fernald has made similar collections 
for me about Orono, Maine, Miss Nellie F. Harvey about Castine, 
Maine, Mr. James B. Graves about Susquehanna, Pa., Dr. Charles 
A. Graves near New London, Conn., Prof. Albert A. Ruth about 
Knoxville, Tenn., Miss Caroline A. Ripley in Missouri and Kan- 
sas, Mr. Charles Mohr in Alabama, and Mr. C. L. Beadle in 
North Carolina. 
To the foregoing and to those who have sent me lesser con- 
