lished until 1828. It is a memoir of some 80 pages, and enumerates 481 plants, many of which were new species. This was, up to the date of its publication, the author's most important contribution to science, and is even now frequently referred to by the student of our Western plants. Besides, it has an especial interest, as it was the first American work of any importance in which the arrangement was according to the natural system. The only earlier publication in which the natural system was used being a list by Abbé Correa, of the genera in Muhlenburgh's catalogue, arranged according to the natural orders of Jussieu.
1831. "A Catalogue of North American Genera of Plants, arranged according to the Orders of Lindley's Introduction to Botany." This was published both in a separate form and as an Appendix to an American edition of Lindley's work.
1836. "A Monograph of the Cyperaceæ."—(Annals of the Lyceum.)
1837. "New Genera and Species of Plants."
1838. "The Flora of North America, by John Torrey and Asa Gray," was commenced and published in numbers, and at irregular intervals, until the year 1843. Dr. Asa Gray, then a young physician in Western New York, who had already shown great acuteness in his investigations of the flora of the part of the State in which he resided, was happily associated with Dr. Torrey in this great undertaking of publishing a "Flora of North America." The work was suspended with the completion of the "Composition," and for sufficient reasons. Just at this time our Government began to explore its Western territory, soon greatly enlarged by the annexation of Texas and the acquisitions by the war with Mexico. New botanical material accumulated at an astonishing rate, and our chief botanists had to choose between continuing the Flora, and allowing these botanical treasures to pass into other hands. They wisely determined to devote themselves to elaborating the new material, knowing that this work would be contributing to the future flora of North America, which, from the enlarged possessions and more thorough exploration of the older territory, must be taken up de novo. Both authors have industriously worked at the collections brought home by the various government and private explorers; those wholly or in large part by Dr. Torrey are here enumerated.
1843. "The Flora of the State of New York," being a portion of "The Natural History of New York." This work is in two large quarto volumes, of over 500 pages each, and illustrated with 161 plates. The descriptions are all redrawn, elaborate, and in a somewhat popular style. It is a most striking testimony to the industry of the author, who, while engaged upon this work, and making important explorations incidental to it, was at the same time discharging his professional duties at the College of Physicians and Surgeons, and at Princeton.
