Ferns from the tropics present to us some of the most beautiful forms to be found in the vegetable world, and now very generally are a portion of collections of exotic plants. Mr. J Henderson, the florist, gives the following directions for their cultivation: - "Procure a number of small octagon-shaped hand-glasses about six inches in diameter, (more or less,) according to the size of the pots intended to sow the seeds in, the side walls of each being high enough to admit the pot to stand underneath without touching the glass.

Pots

These are to be about half filled with well broken potsherds, the finest at top; then fill to within half an inch of the rim with heath-mould, sifted through a fine sieve. Level the surface of the mould, and water it freely with a very fine rose; let the pot stand a few minutes till the water is absorbed, and then carry it to a dry part of the house.

Sowing

Place the papers containing the fern seed for a minute or two on the flue, or some other place where they will become thoroughly dry: then open the paper and carefully dust the spores (seed) over the surface of the moist earth, taking care not to sow too thick. The pots may then be placed in a shady place on a level surface of wood or stone, to prevent the intrusion of worms, and covered with the hand-glass. The germination of ferns differs in different species; some require six weeks and more; and if during that time the surface of the earth in the pots should appear dry, a very slight watering must be given with the fine rose.

After-Culture

It will be necessary to examine the surface of the earth frequently with a pocket microscope, in order to discover any mouldiness or minute algae that may appear; such appearances indicate that too much water has been used; and in that case the glasses should be taken off for a short time, and the pots removed to the full light.

"If aftcr this the mouldiness continue to spread, a knife may be introduced between the pot and the earth, and the latter slightly raised up so as to allow the moisture to drain off.

"As the seedlings acquire strength, they may be removed from the shade to places where they will have more light; but they must not be exposed to the full sun in summer as long as they are under the hand-glass. In winter, however, when the sun is less powerful, all those seedlings that have perfected, or nearly perfected their first fronds, may be exposed to the full light; this will prevent the spreading of mouldiness, which the moist atmosphere under the glasses is so apt to produce at this season of the year.

"When it happens that from too thick sowing the seedlings are much crowded, they should be thinned out carefully with the point of a pen-knife, taking patches of from six to a dozen plants and transferring them to another pot, prepared in all respects as if for sowing spores. In planting these, a slight depression should be made with the point of the pen-knife on the surface of the mould in the new pot, and the patch inserted, taking care not to cover any part of the plants with the earth. They may stand about a quarter of an inch from patch to patch; and when the operation is completed, water the seedlings and place the pot under the glass.

"These transplanted seedlings will frequently succeed better than those in the seed-pots; indeed with very slow growing seedlings it is frequently advisable to transfer the whole to another pot, as they will generally root better in the fresh than in the old earth.

"When the seedlings have fully developed their perfect fronds, (and not till then,) the glasses may be withdrawn. The pot with the seedlings should then be placed in a perfectly shaded place, and more frequently supplied with water.

"They may remain in the seed-pots until three or four fronds are produced, when it will be advisable to shift them into other pots and place them at wider distances.

"Many ferns grow very slowly while in the state of primary frond, and require many months before their perfect fronds are developed.

"It is chiefly for these slow growers that glasses are required; others, such as most of the Gymnogrammas, some species of Nephrodium, Pteris, etc, come up readily in open pots, but with those which require from nine to eighteen months to produce their second fronds, glasses are indispensable.

"Great care must be taken not to allow worms to get into the pots, as they will in a very short time destroy the whole crop. The only way to get rid of these pests, is to place the pot with the glass over it, on a tolerably hot flue, or some other well-heated surface, when the heat ascending through the earth in the pot will drive the worm out.

"It may not be amiss to observe here, that in collecting spores for reproduction, it is better to select a frond on which the thecae (seed vessels) have not opened; if they have changed to a brown colour, and one or two have opened, they will be in the best possible state for transmission to a distance; portions of the frond should then be inclosed in the papers, which should be well secured and kept perfectly dry." - Gard. Chron.