The public have been so recently informed (at least that portion of them who may have seen the new edition of "Downing's Landscape Gardening") respecting the comparative hardihood of evergreens, that but little remains to add to the tabular view in the supplement to that book.

The further experience of two months since this work was published, - two months, which generally are the most trying upon half-hardy plants, - has enabled me to add one or two facts which may be interesting to the planters of new conifers.

While the general list of the newer things has gone through the winter with its usual average success, there are some varieties heretofore untried, which have more than realized the best anticipations.

Both Cupressus Lawsoniana and Thuja gigantea, have at least, this their first winter, done wonderfully well, as with a slight cedar protection they have both preserved their color and character most charmingly, looking quite as green, and feeling as soft and pliable, as the same plants wintered in a greenhouse.

Although the experience of one or two more seasons is required to pronounce unqualifiedly about their entire hardihood, yet, when it is remembered that these trees passed through a temperature of 0/16, upon this place for two days, sufficient to do a great deal of damage to well established and comparatively hardy plants, and even to destroy peach buds, during which excessive cold and ever since they have never faltered or changed color, I feel we have reason to be sanguine as to their complete success.

Thuiopsis Borealis - without any protection, came through equally well; and as this is the third winter it has been out, with me, I consider this tree a fixed fact.

Abies Whitmanniana - or A. Obovata, out for its first winter, is equally successful and hardy.

Cephalotaxus Adpressa - also out for the first time, is entirely hardy, while its older relatives - Cephalotaxus Fortuni, male and female, - have proved themselves beyond question most reliable; especially the male plant. Abies Douglasii - established plants, entirely exposed and perfectly untouched.

Cryptomeria Japonica - of different sizes and ages, and in different positions. Some protected by cedar branches; others entirely exposed, but standing on the north side of a wood, have had equal good luck, and are equally green and perfect.

Cunninghamia Sinensis - in a wood and slightly protected, is not in the least browned.

Cupressus Funebris - with every advantage of shade and protection, is destroyed, and I shall make no further attempt with it, having tried many unsuccessful experiments for several years. (In Phila. uninjured. - Ed).

Pinus Palustris has stood, perfectly well protected; but the specimen tried was a small plant, and was a good deal under the snow, so that I am not willing to pronounce upon it until after further experience.

Podocarpus Andina, Magnolia Galissoniere, (evergreen), and the Portugal Laurel, have all lost or will lose their foliage, but the wood and buds seem sound and good.

If, however, we can be assured of the success of that most exquisite of trees, Cupressus Lawsoniana, and also of the new Thuja gigantea, it is quite sufficient for one winter.

Washingtonia gigantea has stood perfectly well in a wood, but browned on the open lawn. In connection with this tree, I wish to remark, that Meehan's Gardener' Monthly finds fault with my placing it by itself as a separate genus, instead of adopting, I suppose, the English name Wellingtonia, which I have given as its synonym. But how is it possible to describe a plant otherwise than by the name recognized as national by all the amateurs and nurserymen in the country.

Nobody knows this tree as Wellingtonia, or calls it by this name. My impression is that there has always been a discussion between the English and American discoverers, as to who found it first; at any rate, there has been sufficient question about it to justify the pertinacity with which American botanists persist in calling it Washingtonia; and as the tree, whether Washingtonia or Wellingtonia, is a distinct and separate genus, I do not know how my classification can be avoided until we consent to call it Wellingtonia; which, I presume, will never be.

The Gardeners' Monthly likewise finds fault with my classing Mr. Nut-tail's Thuja gigantea as Libocedrus decurrens, and Craigiaha, contending that Nuttall's Thu. gigantea is really figured by him in Michaux as Thuja Menziesii, and partly Thu. Plicata; now in the Traite General des Coniferes, by Carriere, published in 1855, and in Gordon's Pinetum, published in 1858, both the most comprehensive, accurate, and latest authorities on Conifers, I find but one real Thuja gigantea, which is Nuttall's, and synonymous with Libocedrus decurrens, and L. Craigiana, - that is to say, the Arbor Vitae, called by Mr. Nuttali gigantic, is the same tree called by Dr. Torrey Libocedrus decurrens, by Jeffrey Thuja Craigiana, by Lawson Thuja glauca, by Rafinesque Abies microphylla. While the Thuja Menziesii, which the Gardeners' Monthly maintains is the true Thuja gigantea of Nuttali, is synonymous with Thuja Plicata of Lambert, Thuja Lobbii of the Horticultural, as well as Thuja Lobbiana, and lastly, a Thuja gigantea of Hooker, - but both these authors distinctly remark, not of Nuttali. Now I cannot believe two such high authorities (the authorities both in England and France could be so egregiously in error as to represent Mr. Nuttall's Gigantic Arbor Vitae as the only and true gigantea, when he represents it himself as the same as Thuja Menziesii and Plicata, which they distinctly deny.

I am more disposed to believe that subsequent acquaintance and better knowledge of these different varieties have induced these gentlemen to classify them as they have; and although the difference between the two genera of Thuja and Libocedrus may be and is sufficiently distinct when all their characteristics are developed; yet, when the plants are young, the resemblance between them is so strong (for they are nearly allied) that it is not surprising that Dr. Torrey classed as a Libocedrus what Mr. Nuttall called a Thuja, in the same way as the Funebral cypress was by many arboriculturists classed as a Juniper on its first appearance; beside which, when we recollect the Thuja Menziesii only grows forty to fifty feet high, while the Thuja gigantea grows one hundred and forty feet, it would seem a misnomer to call the first Gigantic instead of the latter, which is more than three times its size.