In reply to a correspondent, and thinking it might also interest others of our readers, we give a few notes on the culture of these curious plants. First, it must be noted that all the finest plants of this genus are natives of the tropics, principally growing on trees and rocks in South America and the West Indies, although the well-known, so called, moss found growing on the trees in the Florida swamps, can scarcely be called a tropical plant. There are also a few other larger growing species found in the southern states, growing on trees, but these are of little beauty in the eyes of the general cultivator, the flowers being small and of a dull color. These plants are seldom seen in any but botanical collections, but. can easily be grown on blocks of wood in any ordinary greenhouse. We may mention that all the various genus, in the above natural order, require the same treatment, excepting a few of the very strong growing sorts, such as Brom-elia Karati, and a few others, which in growth so nearly represent the common pine apple, without any valuable fruit, that they are seldom grown. The above-mentioned species thrive with the same treatment given to the pine apple, and need not be mentioned in this article.

The Nidularias, Achmeas, Vresias, Bilbergias, and Tillandsias, are all more or less curious and interesting. Some, such as Achmea Zebrina, have variegated leaves, so nearly the color of a rattle snake, that some of our visitors on first seeing the plant have started under the impression that one of those reptiles had free quarters among the plants; others, such as the Nidularias, have the top foliage of a bright color, and the Tillandsias and Bilbergias have the flowers and floral leaves of the most brilliant and delicate color. The cultivation of these plants is very aim ple; in fact, if allowed to scramble over a rock work in the full sun of a tropical house, they will take care of themselves; but as few of our readers can spare a place for that pur pose, we will give a few notes on cultivation in pots. Achmea Zebrina is a capital plant to grow on the surface of large Aerieles and Vanda pans; it fills the spagnum with roots, and flourishes to perfection. The remaining species we grow in pots; five and six inch sizes are usually large enough, for these plants do not require much pot room, and but little soil, being generally found growing among moss on trees and decayed stumps.

The soil best suited for the plants is rough peat and moss in about equal parts, with the addition of some, sand, grit, or charcoal. The pots require to be well drained, so that water may pass freely, for the plants require a good quantity during the summer, and to be well syringed. In the winter little water need be given, and if in a cool house, must be kept quite dry, and the water not allowed to settle in the crowns, or the heart will decay. In a hot, dry house, the water which collects in the crown like a cup is of advantage, being the natural reservoir to supply the wants of the plant in the dry hot weather of its native locality. Some of the species will make two growths, and flower twice during the year; at the same time there is usually another shoot starting from the bottom to take the place of the one which has flowered, which, like the pine apple plant, only fruits once from same growth. At any time after flowering the old shoot may be cut clean away, but we usually allow the young growth to be well advanced before doing so; frequently there will be roots formed on the young growth; but if not, it can be cut clean away from the old stem and put in a small pot, it will soon form roots if kept rather dry and hot for a time.

Frequently there will be other shoots come from the old stump, which may be preserved if desirable for that purpose. The plant gets on one side from each fresh growth, or it would continue to grow and flower from same pot, without disturbing, for a number of years. A small white scale is sometimes troublesome, and must be cleansed away before it becomes established, or the plants had better be thrown away.

Pot Roses excepting a few required for early flowering, these are best kept in a cold frame, where no watering will be required; those advancing into young growth must have careful watering, and be dusted with sulphur if mildew is seen; in fact, a sprinkle of sulphur is a good preventive, and a light fumigation with tobacco will prevent green fly.