We copy the following interesting account of this superb water lily, and Mr. Cope's successful culture of it, from Dr. Emerson's admirable address before the Delaware Horticultural Society.

The horticultural triumph, of which I have attempted to give you a short description, as it has been recently achieved in Europe, with the aid of the science, skill, and wealth there so abundant, has been promptly repeated on this side of the Atlantic by Mr. Caleb Cope. President of the Philadelphia Horticultural Society, with whose company we are favored on the present occasion. When it is considered that in Europe, the aid of princely munificence has been called into requisition in obtaining the first successful developments of the Victoria Regia at Chatsworth, Kew, and Zion House, the horticultural feat accomplished by our tasteful and spirited fellow-citizen, must be the more highly appreciated. The eclat of Mr. Cope's achievement is only equalled by the kindness he has displayed, not only towards his personal friends, but the public at large, to all of whom bis superb conservatory has been freely opened. More than this, many Horticultural Exhibit inns have, like the present, been supplied by him during the blooming period, with flowers and leaves of the Victoria Regia, which has greatly extended the gratification furnished by a sight so perfect, ly unique.

* On the 21st of last March, Mr. Cope planted in seed-pans four seeds obtained from England, through the kindness of Sir Wm. J. Hooker. Three of these grew, and one of the plants was, on the 21st of May, transferred 'o a circular basin about twenty-five feet in diameter, enclosed in a glazed house erected expressly for the purpose. There it has been kept in water maintained at the tepid temperature of 76° to 85° Fahrenheit. The depth of water in the tank or basin is about two and a half feet, and the oozy soil at the bottom, into which the roots of the plant expands, is about the same depth. It is worthy of notice that the first leaves produced did not exhibit the turned-up edge, or salver-shape, which contributes such an uncommon appearance to to the plant, until about twenty-four had grown. Ever since that peried the leaves have been salvered as quickly as they expanded. The development of a leaf, on first raising to the surface of the water, presents a most curious sight,not easily described.

Rolled into a body of a brownish color, and covered with thorny spines, it might readily be taken for some large species of sea-urchin. The under side of the leaves, as well as the long stems, by which the flowers and leaves seem anchored in the water, arc thickly covered with thorns about three-quarters of an inch long. On the 21st of August, just five months from planting the seed, a flower was developed, and the success of the interesting enterprise thus fully crowned.

As yet Mr. Cope has brought forward only one of the three plants produced from the four seeds. But this has continued not only to keep his tank, large as it is, always covered by its immense leaves, some measuring six and a half feet in diameter - many of which have from time to time been removed and replaced by fresh ones - but also furnished two flowers a week since the first blooming. Some of these flowers have measured seventeen inches in diameter. The petals always open early in the evening, and partially close about midnight. During the daytime, therefore, the Victoria Regia is seldom seen in fullest splendor, unless when removed from the parent stem.

If the development of the leaves of the Victoria Regia present such a singular appearance, the successive movements or changes in the flower are not less extraordinary and far more beautiful.

The crimson bud, which for several days has been seen rising, at last reaches the surface and throws off its external investment in the evening, soon after which the flower petals suddenly nnfold, the expanded blossom, like a mammoth magnolia, floating upon the surface of the water, decked in virgin white, and exhaling a powerful and peculiar fragrance which has been compared to the mingled odors of the pineapple and melon. On the morning of the second day another change is observed and the outer petals of the flower are found turned backward or re-flexed, leaving a central portion of a conical shape surrounded by a range of petals, white on the outside but red within. A slight tint of pink is discernible through the interstices of of these petals, which increases as the day advances. In the evening, about five o'clock, the flower is seen to be again in active motion preparatory to another production. The white petals, which were reflexed in the early part of the day, now resume their original upright position, as if to escort their gay colored companions surrounding the central cone to the limpid surface below. After this the immaculate white of first bloom changes to gay and brilliant pink and rose colors.

Finally, a third change ensues, marked by the spreading of the petals further backwards, so as to afford the enclosed fructifying organs liberty to expand, These are soon seen to rise, giving to the disk of the flower a peach -blossom hue, the stamens and pistils at the some time assuming a figure not unlike that of the old regal crown of England. On the third day the flower is nearly closed. All the petals seem suffused with a purplish pink; the coloring matter, which was originally only seen in the centre, having apparently penetrated the delicate tissues of the entire flower.

The leaves exhibited here do not belong to the plant which produced the magnificent flow. er before yon, but were taken from a garden tank in which Mr. Cope has brought forward the lily under glass, without the assistance of stove-heat. It is true this lily has not yet bloomed, but the fine development of leaves gives reason to believe that, with the aid of a warmer sun than they have in England, the Victoria Regia may be brought to perfection in ihis country, even without artificial heat. In order to give it every advantage, it will still be necessary to start the plants in seed-pans placed in hot-bels, or heated conservatories.

In concluding this brief account of the Victoria Regia, I may observe that to German and French scientific explorers of primeval forests, is due the honor of first discovery and description, whilst to British activity and perseverance we are indebted for the introduction of this great floral prize into England, from whence it has been brought to our own country. Mr. Cope has succeeded in his first experiment, in producing the Victoria Regia with larger leaves and (lowers, than any yet reported as having been raised in Europe. In his conservatory floats the Queen of Flowers in all her beauty, attended by her natural but strange-looking subjects, the orchids, suspended around in groups, and mingling their fragrance with her own. In fact, the whole scene presented in the lily-house is unique and highly impressive, well calculated to awaken poetical conceptions, among which it is easy to imagine a shrine consecrated to an oriental goddess, or grotto dedicated to water-nymphs, and presided over by aegle, the fairest of the Naiades.