PREFACE. ix 
things are quoted from the incomparable descriptions of Bige- 
low. I am under obligations to Dr. Gray for suggestions in 
regard to the distribution into families and genera; but I should 
be sorry, to have him considered responsible for any thing 
in its execution. Mr. Oakes has furnished me with many 
beautiful specimens, such as nobody else can make. To Mr. 
Russell, I am indebted for a communication upon the Pitch 
Pine, and for other favors, as well as for the catalogue of 
Mosses. ‘To my friends, Messrs. E. Tuckerman and B. D. 
Greene, I owe thanks for the use of specimens from their exten- 
sive herbaria. Dr. Barratt, of Middletown, Conn., has given me 
important assistance in the study of the Poplars and Willows; 
and from the invaluable Report of my friend Dr. Harris, I 
have, with his consent, obtained much information, not to be 
found elsewhere, in regard to insects. 
T'o so many citizens of the Commonwealth am I indebted 
for aid received in conducting the Survey and ascertaining the 
condition of the forests, that I can do no more than mention 
their names. From Hon. D. P. King and Messrs. 8. P. Fowler, 
of Danvers; Josiah Newhall, of Lynnfield, and Lilley Eaton, of 
South Reading; J. L. Lewis, of Hmgham, Samuel A. Turner, 
of South Scituate, and my friend G. P. Bradford, then of Ply- 
mouth; from Messrs. Chester Adams, of South Natick, and 
Daniel Adams, 3d, of Newbury; Daniel Davis, of Fairhaven, 
Thomas A. Greene, of New Bedford, and Hezekiah Barnard, 
of Nantucket; S. Davis, of Truro, Solomon Freeman, of Brews- 
ter, and E. Swift, of Falmouth; from Messrs. Jabez Newel, and 
Abijah M. Ide, of South Attleborough; Rhodolphus Sanderson, 
of Kast Whately, and D. Willard, of Greenfield; C. B. Rising, 
of Worthington, and Joseph Field, of Charlemont; C. 8S. Dar- 
ling, of Gill, and Samuel Mixter, of New Braintree; Allen C. 
Metcalf, of Lenox, J. H. Cobb, of Dedham, and 8. Salisbury, 
of Worcester; from Henry Colman, of the Agricultural Sur- 
vey, and especially from Wm. Bacon, of Richmond, Austin 
Bacon, of Natick, and Henry W. Cushman, of Bernardston, 
I recerved very useful letters,—from the three latter gentlemen, 
communications of great value. 
From Messrs. P. T. Jackson, N. Hale, Ch. L. Storrow, B. T. 
Bb 
