The Greenhouse will be the principal point of attraction during the present month; for, excepting a few Chrysanthemums in sheltered nooks, there will be few flowers remaining out of doors in the north and middle States; so that every attention should be paid to keeping the house as neat and attractive as possible, by attention to clean pots, and removing dead leaves, and placing the most attractive flowering and foliage plants in the best position. Now is also a good time to carefully examine all plants likely to be infected with insects. There is usually more leisure for that kind of work at this season, and most plants having completed their growth, will bear more handling without injuring the foliage, than at an earlier date.

Camellias should be sponged over the foliage to remove dust, before the flowers commence to open; it not only improves the appearance of the plants, but is a great benefit also. If any of the plants have traces of red spider, some sulphur and whale oil soap should be mixed in the water used; for nothing but dust, clean water is best.

Azaleas must be kept cool if required to flower late; and although at this season, when at rest, they do not require frequent watering, care must be taken that the plants do not get very dry, and that a good soaking is given when required. . Young plants, and any required to flower very early, must be placed in the warm part of the house; but in this, especially, thrip will require guarding against, or much damage will be done. But all the plants should have a thorough washing with soap and tobacco water at this season, as previously recommended. This will usually prevent much trouble from insects during the succeeding season, unless the plants are neglected.

Bourardius must be placed in the warm part of house, if expected to flower well. If the house is not kept above 50° at night, little beauty must be expected from these plants.

With careful watering and a regular heat these plants are easily grown, and will be free from insects; but if the heat is irregular and infested plants are near, nothing becomes more dirty; but if grown in a very high temperature, the flower lasts but a short time after being cut. This also applies to many other winter flowers and foliage when cut.

Orchids - We have received so many inquiries about this interesting class of plants, which it takes too much time to answer separately, that we considered a few general hints would be acceptable to our readers, without devoting a long paragraph to an individual species. Dendrobrums will have completed their growth for the season, and must be placed in the full sun and kept dry, but not allowed to shrivel, or the flower will be small. The principal thing is to get a good, strong growth, and to well ripen it, when the plants will be sure to flower. Cattlegas will have finished growing, except the Trianae varieties, which flower during the winter from the young growth. These all require plenty of light, and to be kept moderately dry; but in this climate few species require to be kept so dry. as in England, especially when grown on blocks. Oncidium, Cavendishii, and Ornithorhyncum will now be in flower, and must be placed in shade from bright sun, or the flowers will soon fade. The crinitum varieties of Zygopetalon will be in flower, and must be watered when required.

These are fine and easily grown, and the flowers last a long time in full beauty.

Cypripedium Insigne is one of the best winter flowering plants we have, and requires no special treatment. It will grow and flower well in any greenhouse. We usually grow our plants in the Camellia house, and remove them to a house a trifle warmer about this time. The flowers of this species will last for three months in a greenhouse or sitting-room. These plants must never get very dry, although in a cool house at this season they do not require watering often. Most of the other species of Cypripedium require a little more heat than the above, and are chiefly summer bloomers, except Raezli which in strong plants will flower all the year.

Laelias are splendid winter orchids, such as anceps, Superbiens Autumnalis, Acuminata, and Albida, can all be depended on for winter flowers, and grow best in a cool house. These last for a very long time in full beauty, with little attention. Stanhopeas, if grown in baskets, will require no water for several weeks; if grown on blocks, must be soaked in tepid water occasionally. We may mention that it is necessary to grow these plants either on blocks or in baskets, for the flower spikes come from the bottom of the plant, and if grown in pots has not power to develop itself. All this class of plants is subject to a small, white scale insect, which must be removed by occasional sponging with water.

Chinese Primulas will now be in flower. These plants require careful watering. If wet over the foliage, they often rot off at the surface of the pot. The double white variety is one of the most useful winter flowering plants grown.

Cinerarias require to be kept cool, in a damp part of the house, for in a dry atmosphere they are very subject to thrip, red spider, and green fly, and will require gentle fumigating with tobacco, but are easily injured if the smoke is very strong and hot.

Verbenas must be kept cool, and well supplied with water. A little frost does these plants less harm than a hot dry house. These plants should be fumigated once each week, as a preventive, Pelargoniums and Geraniums must not be over watered, and receive as much ventilation as possible, without exposure to cold, drying winds, widen would brown the edges of the leaves.