the localities or habitations of such plants may be, as those from opposite latitudes or zones of a great distance, with a similarity of soils. This is applicable also to seeds derived from the parent stock of stunted growths, otherwise physically deteriorated constitutions of such plants growing on mountains, in sheltered positions, shady ravines, or in soils or positions presenting no similarity. It is well known to every accurate observer, that powerful summer heats are capable of causing trees and shrubs to endure the most rigorous winters; which would militate decidedly against the opinion of some as to the acclimation of plants from Southern to Northern latitudes. Seeds contained in pericarps germinate sooner if planted immediately after being separated from their natural covering. I do not think that the mean annual temperature of various countries in the temperate zones and tropical regions affect the growth and nutrition of plants so much as has been supposed. The habits and life of a plant may be changed, and brought to exist on food not naturally suited to its constitution by the care and cultivation of the same by man, who is the most active agent in the dispersion of plants. Many plants, as those the most useful to mankind, by slow and gradual acclimation, become distributed over a vast region; as a proof of this position, we have only to point to the Indian corn, rice, cotton, and sweet potato, growing in our own country. Again,-plants, whether herbaceous or perennial, as in medical botany, may, by removal from opposite zones, become stunted in their growth, with less luxuriance of appearance, yet there will be a greater concentration of active properties, than what is possessed in its original habitation. The designs of our Creator are obvious in all of his works. Without care or much protection by man, we see the delicate plant, Nastúrtium peruvianum, or Indian cress, braving the different climes, and lingering on the verge of our Northern winter. This plant is a native of Peru; its systematic name is Tropœ`olum majus, from Toαov, or Tropaion, a warlike shield or trophy. "This fanciful but elegant name was chosen by Linnæus for this singular and striking genus, because he conceived the shield-like leaves and the brilliant flowers, shaped like golden helmets, pierced through and through, and stained with blood, would justify such an allusion." It was first brought to

France from Peru, S. A., in 1684: in its original state, it is said to be found growing to a considerable height, forming quite a tree.

I cannot refrain from expressing the most earnest wishes for the success of our enterprise in establishing an Experimental Garden in Florida, for the cultivation and acclimation of tropical plants. The feasibility of the plan is so clear that the national advantages derived therefrom cannot but strongly impress the public with the ulterior benefits which will grow out of its foundation when brought to maturity. As it will be the means of introducing many of the most valuable plants of the tropics from distant regions, promoting agricultural science, increasing the original material of our manufactures, adding largely to our staple commodities and commercial exports, and, above all, diffusing a love for the cultivation of plants in the rising generation, that will permanently base and characterize us as an agricultural nation. With great esteem, I am, dear sir, very respectfully yours, AUGUSTUS MITCHELL, M.D.

HON. H. A. S. DEARBORN.

We have already expressed our opinion of Dr. Mitchell's papers, which possess great value, and we are gratified in being the medium of communication, through General Dearborn, of his letters. For his complimentary notice of our labors in the science of Horticulture, we feel highly honored. Another excellent letter is postponed, for want of room, to our next. -Ed.

ART. IV. Descriptions of Eight New Varieties of Prairie Roses. By the EDITOR.

No productions of the flower garden have attracted more attention within a few years than the new and beautiful varieties of Prairie roses, which now form the principal ornaments of every good collection during the month of July, after other roses have gone. Mr. Feast, who was the first to give a new feature to our native Prairie, deserves the thanks of

354 Descriptions of Eight New Varieties of Prairie Roses.

every lover of this beautiful tribe for the origination of his superb seedlings. For years, we have been cultivating foreign roses, very few of which, in comparison with the Prairies, deserve a place in the garden. Some of the Boursaults are exceedingly showy and brilliant, but, with few exceptions, they, like all other varieties of climbing roses, must give way to the Prairies.

Two years ago, we gave a full descriptive account of all Mr. Feast's seedlings, (Vol. X. p. 246,) with a view to correct any errors which might have arisen in the dissemination of the kinds; and we believe our article was the means of enabling cultivators to detect mistakes, and the different varietics are now readily obtained under the correct names.

It is well known that, since Mr. Feast produced his fine seedlings, our correspondent, Mr. J. Pierce, of Linnæan Hall, near Washington, D. C., whose place we have twice noticed, has raised several new and extremely beautiful varieties, some of them vieing with Mr. Feast's, while others much excel them. Mr. Pierce raised twelve kinds, brief descriptions of which he sent us last season; but, as they only referred to the color of the flowers, we thought it preferable to delay their publication until we could render them complete. Most of our plants have flowered finely this year, and we have been enabled to do so, and we now annex the following descriptions of each :

ANNE MARIA.-Flowers, medium size, pale pink, with rose centre, cupped and very double: clusters, large, numbering twenty to thirty flowers, and rather compact: foliage, medium size, very pale green, undulated, slightly serrated, and rather smooth spines, strong, pale green: habit, robust, vigorous and good. It is quite distinct from any of the others.

EVA CORINNE.-Flowers, large, very delicate blush, with beautiful carmine centre, globular, and very double: clusters, medium size, containing from ten to twenty flowers, rather compact foliage, medium size, rugose: spines, purplish : habit, vigorous, and very erect. This is the most delicate of all the Prairies, and its clusters of blush flowers, with their deep centre, which are perfectly globular and quite fragrant, entitle it to a prominent place in every garden. It blooms quite late.

MISS GUNNELL.-Flowers, medium size, of a delicate blush or buff, precisely of the shade of Lady Hume Camellia, cupped, very regular, and double: clusters, large and spreading, numbering twenty-five to thirty flowers: foliage, large, undulated, and partially rugose: habit, vigorous and good. This is quite unique for the delicate tint of its flowers, which are produced in large clusters. It is one of the very best.

JANE.-Flowers, medium size, of a beautiful light, or lilac, rose, imbricated, and very double: clusters, large and rather compact, numbering twenty-five or thirty flowers: foliage, large, coarsely, and sharply serrated: habit, very strong and vigorous.

RANUNCULIFLORA.-Flowers, small, pale blush, very much resembling Baltimore Belle: clusters, large, usually twenty or thirty flowers: foliage, very rugose: spines, purplish: habit, vigorous and good. This variety is slightly fragrant, and flowers rather late.

PRIDE OF WASHINGTON.-Flowers, medium size, pale rose, cupped and double, somewhat resembling Jane: clusters, medium size, numbering ten to twenty flowers: foliage, medium size, slightly serrated, and nearly smooth: habit, vigorous and good.

TRIUMPHANT.-Flowers, medium size, deep brilliant rose, imbricated, very double, and finely formed: clusters, large, and rather compact, numbering from twenty to thirty flowers: foliage, very large and handsome, undulated and bright green, deeply and sharply serrated: habit, very strong and robust. This variety is remarkable for its ample and beautiful foliage, as well as its deep and brilliant rosy flowers.

PRESIDENT.-Flowers, small, deep pink, compact, and very double clusters, medium size, and rather loose, numbering fifteen to twenty flowers: foliage, medium size, rugose, and rather deeply serrated: prickles, purplish red habit, vigorous and good. This is one of the latest flowering varieties. These are all Mr. Pierce's seedlings, eight in number. We have four others, which have not yet flowered sufficiently strong to give a correct description: their names are, Mrs. Hovey, a superb white; Virginia Lass; Linnæan Hall Beauty, and one unnamed. Another season they will probably bloom in fine condition. Mr. Pierce speaks very highly of

Mrs Hovey, as being a fine white, the "largest, doublest and best" of all his seedlings; it is of superb habit, with splendid deep green foliage, and, if it proves a pure white, it will be the greatest acquisition which has yet been made.

In our volume for 1844, (X. p. 98,) will be found an article by Mr. Pierce, upon the Prairie rose, with some remarks on its employment for hedges or live fences. In that article he states, that, having sown a lot of seeds for the purpose of stocks, "he was not a little surprised to find that he had among them twelve fine varieties of double roses." It would be gratifying to amateurs to know how he procured the seed by which he should be so very successful in producing these double varieties; whether they were from the single Prairie, or from the double varieties-or whether they had been impregnated with other sorts. We trust Mr. Pierce will find the opportunity to communicate this information, that those who wish to follow up his experiments may have some guide as to the best method to adopt to attain the end in view.

To Messrs. Feast and Pierce, the lovers of the rose are deeply indebted Mr Feast, we are gratified to know, has received some reward for his beautiful productions. We trust that Mr. Pierce, whose seedlings are fully equal to any which have been raised, will, in due time, also receive that token of merit which is justly his due.

ART. V. On the Propagation of Stove and Greenhouse Exotics: in a Series of Letters. By JAMES KENNEDY, Gardener to S. T. JONES, Staten Island, New York.

LETTER IV. Propagation by Layers.

THERE are many kinds of Exotics, such as the Myrtus, Jasminum, Nèrium, Pùnica, &c., which succeed best by this mode of propagation, and, indeed, it may be considered the most certain mode of propagation by division. The great advantage it has over any of the other modes is, that the part layered receives nourishment from its parent while roots are being formed, whereas cuttings get no further supply than