The weather may probably be now severe, and it is at all times advisable to keep the temperature as steady and regular as possible. The thermometer should be kept in the centre of the house, and free from the effects of reflection. As noticed last month, sun heat may be as high as 50° in the house, and would not be hurtful, but it should not continue so for any considerable time without admission of air. The fire heat should not exceed 43°, and never be below 33°. It ought not to continue at that point—36° is the lowest for a continuation that with safety can be practised. So that no error may occur, the temperature ought to be known in the coolest and warmest part of the house, and the variation remembered. Then whatever part of the house the thermometer is placed, a true calculation of the heat of the whole interior can be made. We would recommend to the inexperienced to keep the thermometer in the coldest part of the house. A Green-house compactly and closely built, and the glass all covered with shutters, (which no house ought to be constructed without,) will seldom require artificial heat; but by being long kept close, the damp will increase. In such case give a little fire heat, and admit air to purify the house. In fresh mild weather, give liberal portions of air all over the house; and though there is a little frost, while mild, and the sun shining, the plants will be benefited by a small portion of air for the space of an hour, or even for half of that time.

Whatever state the weather may be through the winter, never keep the house long shut up. Thirty-six hours, or at most sixty, should be the longest time at once; rather give a little fire heat.

We are no advocates for keeping plants long in darkness, and never think that our plants are receiving justice, if kept longer in darkness than two nights and one day.

Respecting watering and other necessary operations, see next month particularly.

BULBOUS ROOTS.

Those that were plunged in the garden, if not lifted and brought under cover, should now be done without delay. Clean the pots, and stir up the surface of the soil. Hyacinths grow neatest by being kept very close to the top glass; the flower stems are thereby stronger and shorter. Water moderately until they begin to grow freely.