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 sjiionyms of 

 Dr. Sherard, and frequently accompanied with the ori- 

 gmal letters of M. Catesby. In the same collection are 

 also a lumiber 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, I 

 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 Willde- 

 novv's "Species Plantarum" and Michaux's "Flora 



