Letter of Dr. Muhlenberg. (Copy of original in Library of Academy of Natural Sciences, Philadelphia).

Lancaster, Oct. 29, 1814.

Dear Sir: - Your letter of the 20th of October arrived safe and gave me much pleasure. Probably Mr. Michaux's letter will contain some news of what we can expect from him in a future day on American Shrubs. He has deserved well of trees: will the English translation appear as promised and can you not persuade him to add a few Synonyma? At least his father's Synonyma should be added, Tilia Nyssa and a few others are still doubtful.

After examining the Prunus pygmaea of Willdenow's Specimen I have no doubt he means our Long Island Beach Plum. My son mentions they have two varieties on the New York market: the small one agrees entirely with pygmaea, the larger one is hardly more than a variety; can this be the maritima Willdenow? I have put both in my garden, but shall hardly live to see the difference. As P. sphcerocarpa Mich, must change its name the former name can remain for maritima or pygmaea.

The Prunus cerasifera, - Willd, I have seen several years without knowing it. It is not our common wild yellow and red Plum, the Americana, Marshall, although the description of Ehr-hart agrees very well. It is a round, red Plum with a compress drup - "caule biorgeali, ramis glabris foliis ovatis utrinque acutes obtuse serratis venesis basi subglandulosis floribus odoratis soli-tariis." It stands in Mr. Matlack's (now Gun-dacker's) garden at Lancaster. Mr. Matlack had it by the name of South Sea Plum grafted. I have no doubt it is a North American Plum, and wish to hear more of its native place. Mr. \V. Hamilton thought he knew it. Will you favor me with your opinion. At Baltimore they have another wild Plum on market which was named to me Mountain Plum, but the specimen sent to me was not different from the P. Chicasaw Mx. The P. acuminata and hyemale Mx. are still uncertain to me. If I could get a sight of P. nigra Bot. Mag. 1117, I would be much pleased.

Of Mr. Bigelow I have heard nothing since, nor of Mr. Green, nor of my Southern friends Elliott and Baldwin. The mournful news of the departure of Lyons, I have mentioned to Mr. Elliott.

If Mr. Correa returns by the way of Lancaster I shall be extremely glad to see him, and if I could then persuade him to take charge of my Catalogue with a few specimens to Messrs. Per-soon and Beauvois or a few seeds for Thouin I would be much pleased.

Forgive me that I trouble you so often with my trifling letters and let me hear very often that you are in good health. I remain with great esteem, Sir, your sincere Friend.