PREFACE. 
xviii 
anxious to examine it. Dr. G. Williams, professor of bo- 
tany in that University, received me with that kindness 
so congenial to the true friend of science, and supported 
my researches to the utmost of his power. Besides the 
entire Herbarium of Morison, and other valuable collec- 
tions, I found a general collection of North American 
plants, among which I was particularly gratified to find 
all those sent by Mr. M. Catesby to Dr. Sherard. This 
collection, though made a century ago, is in very fine 
preservation, and contains specimens of most of the 
new species of Walter, Michaux, &c. and even some 
entirely new ones, with the remarks and synonyms of 
Dr. Sherard, and frequently accompanied with the ori- 
ginal letters of M. Catesby. In the same collection are 
also a number of rare specimens collected by a Mr. 
Tilden at Hudson’s Bay, and those of John Bartram 
and other correspondents of Dr. Sherard. In fine, 1 
consider this the most complete collection of North 
American plants now extant. The notes and remarks 
made here are given in the Appendix and Addenda, as 
it was not until the body of the work was printed that I 
had the opportunity of seeing this valuable collection. 
Having thus given a. general view of the means and 
resources I had in composing the present work, I shall 
only add a few remarks respecting its execution. 
On a slight inspection of the work, it will be readily 
perceived that my chief object has been, throughout, to 
comprise as much matter as possible in the smallest 
space which attention to perspicuity would allow. 
In respect to nomenclature I have followed Wilkie - 
now’s “ Species Plantarum” and Miehaui’s “Floea, 
