Green-Fly, or Aphis, is one of the most common, but fortunately most easily destroyed, of any insect that infests plants, either in-doors or out. In our greenhouses, as already stated, we fumigate twice a week, by burning about half a pound of refuse tobacco stems, (made damp), to every 500 square feet of glass surface, but in private greenhouses or on plants in rooms, fumigating is often impracticable. Then the tobacco stems can be used by steeping one pound in five gallons of water, until the water gets to be the color of strong tea. This liquid applied over and under the leaves with a syringe, will destroy the insect quite as well as by fumigating, only in either case the application should be made before the insects are seen, to prevent their coming rather than to destroy them when established; for often by neglect they get a foothold in such legions that all remedies become ineffectual to dislodge them. Another means of preventing the green-fly is to apply tobacco in the shape of dust. The sweepings of tobacco warehouses, which can be found for sale in most seed or agricultural establishments, at a cost of five to ten cents per pound. This applied once or twice a week to an ordinary sized private greenhouse, would effectually prevent any injury from green-fly. No special quantity of this need be prescribed, all that is necessary is to see that it is so dusted on that it reaches all parts of the plant and on both sides of the leaves. It is best to slightly syringe the plants beforehand, so that the dust will adhere to the leaves. When applied to plants out-doors, it should be done in the morning when the dew is on. Fruit-trees of many kinds, shrubs, and Roses of all kinds, out of doors, are particularly liable to injury from some species of Aphis, but the application of tobacco dust, if made in time, will be found a cheap and effectual remedy.