Who does not like this beautiful class of plants? Or what could be more interesting to botanists than to study the curious structure of their reproductive organs; or to a gardener or amateur to see side by side, the innumerable species and varieties, differing so much in structure of their fronds, from simple to compound, varying in form extremity, dentation, lobation and decomposition.

Ferns inhabit all parts of the globe, varying much in structure; some attain a height of twenty feet or more, while others scarcely rise an inch from the ground. So the mode of growth differs; some make compact tufts; some again send their creeping rhizome between stones and neighboring trees; some are ascending, others climbing; some send their fronds from a short caudex, while others have a high, tree-like trunk to support their noble heads.

Owing to the great diversity in their structure, habit and geographical distribution, ferns can be used to every purpose. The hardy ones for covering walls, rocks and marshy places; for decoration, again, are the greenhouse and stove kinds of great value. The tree ferns are generally adapted for large conservatories, while the smaller ones are unsurpassed when intermixed with flowering and ornamental leaved plants; and, again, there is scarcely a bouquet made that the lovely fronds of maiden-hair fern would not adorn. Most ferns are found growing in moist places, well sheltered against wind and direct rays of the sun; along the river banks is their favorite place, but some grow in marshy places, partly in water; some again on dripping rocks, or in caves, where they never receive any sunshine and but little light; and it is only a very limited number that are found on dry rocks exposed to wind and the burning sun. These conditions are very essential for the grower to know, which should be imitated as far as practicable.

Like the rest of plants, so ferns have their enemies; the two worst are the small snail and the thrips. The small snail is very destructive, especially in spring, when the plant starts to grow. As soon as it is noticed that any of the young growths have been eaten away, the plants should be looked over, destroying all that are caught, and then putting round the pots, or benches the plants stand on, a row of dry ashes or sawdust, which sticks to their body and thus prevents them from crossing it. In case of thrips, the most affected parts should be cut away and the plants sponged over with a light solution of soap water. Different kinds of scales, also mealy bugs, sometimes make their appearance, and they should be kept down by frequent inspection and brushing off all that can be seen.

From a cultivator's point of view, they can be divided into stove, intermediate, cool and hardy, tree and filmy ferns. The stove kinds require a mean temperature of 65°, the intermediate 50°, the cool, or half hardy, should just get protection against frost, while the hardy ones, if planted in the condition they are naturally found growing, require scarcely any care. Tree ferns may be classed with the intermediate, while the filmy ferns are divided into stove and cool; the latter stands a few degrees of frost without injury.

The best time for planting or re-potting ferns is just as they show signs of growing in the early spring, especially the deciduous species, which hold the majority among the hardy ones, but are few among the indoor kinds. In re-potting ferns, the most important points are good drainage, firm potting, elevating the plant a little above the rim of the pot or pan, so that water does not lodge in the crown of the plant, and last, but not less important than the preceding, is to avoid over-potting, so that when transferred into a size larger pot they keep good and sound ball; and it is only in this condition you see healthy plants. After being re-potted, which takes place about the month of March, water should be given very sparingly until the new roots have traversed the added compost. The atmosphere in the house should be kept humid by frequently dampening the floor, with only very little ventilation, while the temperature should be raised 50 to 1o°. This treatment will help the young growth and roots considerably, but in measure, as the fresh growths and roots advance, more air should be admitted and a liberal supply of water given all the summer and fall.

In winter the temperature should be lowered, and only enough water given to keep them alive; by this method they will receive a good rest, and make much more vigorous growth the following season.

Shading the houses is another point, nearly all the ferns requiring more or less of that attention, especially in spring, as the young shoots are easily burned, and thus disfigure the plants for the season. But shade should be given only in sunshine, and removed afterwards, in order to give all light possible to get their growths well matured. The tree ferns require scarcely any shade, while again every ray of sun should be kept from the filmy kinds.

In regard to syringing, the filmy ferns should be seen to twice a day in summer, and once in winter; the tree ferns on every bright day in summer, seldom in winter. It is the general opinion that ferns should not be syringed, but I found that a light syringe on a bright morning, about once or twice a week, in the growing season, is very beneficial to the rest of ferns, with the exception of gymnogrammas, which should never be syringed.

The propagation is effected by dividing the plants in the spring, just when they start to'grow; they are also very readily raised from spores, and many interesting new varieties were raised by this method, which is the best mode of propagation, where these plants are wanted in quantities. Botanic Gardens, Cambridge, February 16, 1884.