As many of our readers ore aware, the Pennsylvania Horticultural Society, by the recommendation of its special committee, abandoned its Fall exhibition and united with the Pennsylvania State Agricultural Society. The immediate cause of this step was the destruction, by fire, of the usual hall of exhibition which had been annually hired for the purpose for some years past.

We took for our annual horticultural feast, what had been provided by a committee of the Society, acting under the direction of the executive committee of the State Agricultural Society, and now proceed to notice a few items of interest which occurred to us to be note-worthy. And here we may state, that if the Floral Tent or Hall had been dust-proof, instead of dust-producing, we might have recorded the display of plants and flowers to have been equal to any previous d splay, and the specimens of green and hot-house specialities as unequalled at any previous annual exhibition of the Society; but dust, dust, obscured the tints of the petals, the marbling of the beautifully variegated foliage of our choicest favorites, the healthy and refreshing green of the once glossy leaves, ruined all, and disgusted every fastidious dust eater; and the fruit, which on all occasions is but too tempting, was secured on the second day from all officious and unprivileged critics, unless those who were so fond of fruit as to eat it at the peril of an extra ounce or two of dust Have we said enough of the dust? no; we felt far more; we could not discolor and Maranta Zebrina were all in all.

We had to wipe off the deposit before we could recognise the ground color.

Several of the liberal amateurs of the city sent their fall-grown specimens to decorate the hall. Those plants (on a former occasion, designated hop poles by a aiterieal correspondent of your Magazine) have their uses, and without them the Floral Hall would have looked bare and unsightly. To those from a distance, who have read and not seen the curiosities of the tropical forests, these much abused specimens are objects of intense interest Many of our country friends have read of, but not seen the Indian Rubber tree, the Cinnamon tree, the green and black tea plants of commerce, the Camphor plant, the Cocoa tree, and many others noted in the arts, and famous in domestic circles. Most of these may be seen and admired on such occasions, and though their aspect and dimensions may not please the critical eye of the "working gardeners" of our day, they are pleasing to the less fastidious visiter who reads as he runs.

In addition to such valuable plants as we have adverted to, from the conservatories of the vicinity, there were for competition a most valuable collection of green and hot-house specialities. Cissus discolor, with its remarkable and by-all-admired foliage, was most conspicuous; for the specimens deposited from the garden of Jos. Dundas, Esq., by Mr. Pollock; from R. Buist's nurseries, by Mr. Sutherland; and several other well grown and trained plants, were equal to the highest expectations of those who had seen it in the earlier stages of its cultivation. Trained on a suitable wire or wood trellis, we cannot find, among late introductions, a more splendid object. Gardenia Devoniana, somewhat rare, was in good condition; the flowers at first sight resemble those of G. Stanleyana, but are of a cream color inside, as well as outside; the tube of the Cololla is elongated, as in Stanleyana, and the Stigma is club-shaped, by which the species may be readily distinguished. Very fine specimens of Allamanda neriifolia, Cathartiea, Aubletii, and others, were among these collections. Large and well grown plants of Clerodendron ktempferii, squama-turn, fallax, and others, attracted attention by their ample dark green foliage and bright scarlet flowers.

We also observed a fine specimen of Stigmaphyllum ciliatum - a very choice climber, with carious yellow flowers. Several new Begonias, such as Xanthiua and Prestoniensis, Pasei-flora alata superba, Ipomea ficifolia, Schubertea graveolens, Scutellaria Veqtenatii, Dioscorea discolor, and many other more familiar green and hot-house plants, seemed to us worthy of notice. Our readers who are interested in these details must excuse our particularizing more fully the various objects, and the cultivators who deserve honorable mention.

In addition to plants, there were several displays of cut-flowers. One collection of 24 Dahlias was very choice, for the season, which was against the development of the points of this fancy floral favorite. A stand of Verbenas was also much admired, before the clouds of dust obscured their bright tints. We noted a great number of dwarf Asters, or Queen Margarets, from M. Souchet, Woodbury, N. J., late of Paris. They were much admired by the amateurs who depend for flowers on their city yards, for they were familiar objects to them. A very fine display of variegated plants was exhibited, similar to that noticed at Brooklyn. They were among the most attractive objects on the ground - carefully selected, and of great vnlue. Also, a little stand of box, filled with small variegated novelties, and interspersed with Lyooprodinms and Mosses, was neatly arranged and tastefully conceived. We were much struck with a collection of prepared specimens of the Algae, or sea weeds, in large glazed frames, suspended in the Floral Tent. We confess to a little scientific predilection, and cannot pass these splendid specimens without a word.

We have to furnish at another time Mr. Sommerville's method of floating these unusually large specimens, by an apparatus of his own invention, the full details of which he kindly placed at our disposal Algae deserve a little more attention, even in a commercial point of view, than they receive here.

The fruit department has now to be noticed, but to do it justice would require more space than we can at present appropriate to it; a passing glance is all we need attempt at present There was a large display of choice Apples - some fine specimens from the western country. Ohio and Michigan had their representatives. A fair display of Pears was to be found on the tables; their quality and history we must leave to those gentlemen who were set apart to the agreeable work of dissection and gustation. The grapes we could judge of ourselves. A bunch of Black Hamconspicuous; it might be described as a bunch consisting of three shoulders, as the principal and two shoulders were equally large. The wood was unusually strong, a portion of the cane having been cut with the bunch. We should like to learn the history of that vine for the previous and future season. There were several other displays of Exotic Grapes. A number of varieties were exhibited by R. Buist, Rosedale nurseries, several of them new sorts, or at least not yet in general cultivation here.

The Brineklé Grape was also deposited, for the history of which we may refer to previous reports, and for its quality to those who tasted it It is a seedling raised here from foreign seed. (Is this a native grape ) The specimens of Watermelons, were very fine. We can say so much, as by special favor we were permitted to taste several of them, alter the judges had proceeded to their satisfaction. Several baskets of good looking Peaches were among the fruit observed by us; but as no one can report so well of this department as the three gentlemen who had the authority to do so, we leave it for them, and hope to have a note of any thing new and interesting before next month.

The Vegetables far surpassed our expectation, there were extensive lots from Girard College garden, gardener, Mr. J. Jones, consisting of sixty-seven varieties - all of them superior in size. From the Pennsylvania Insane Hospital, gardener, Mr. Reilly, the display was respectable. Mr. Felten, market gardener, had a very large table covered with an immense variety. Near the vegetables we discovered some leaves of the Victoria regia out of its element, and not at all attractive, as by some mismanagement (strange to us), the tank prepared for it could not be filled; it was a box lined with green braze cloth, and absorbed a large amount of water. One solitary leaf was be seen floating in it, while in various parts of the hall we were questioned as to where Victoria Lily could be found, proving that public taste has not yet abandoned this giant of the soft and perishable section of vegetable nature. No better opportunity has ever been afforded for displaying it to advantage - none less carefully improved.

Leaves of the Nelnmbiam speciosum were also contributed by Mr. Cope, as well as a living plant; but it may have been supposed that the lily of the Amazons, with its aristocratic title, would prove obnoxious to the democracy of Pennsylvania. There may be something in it! We refuse to cry Wellingtonia gigantea after John Lindley, though the great Conifer of California is worthy our highest veneration next to the supreme providence which gives his children such evidences of his silent power. S.